QtWidgets: Use Q_NULLPTR instead of 0 in all public headers

This is in preparation of adding -Wzero-as-null-pointer-constant (or similar)
to the headers check.

Task-number: QTBUG-45291
Change-Id: Ie67d235151ca8d4ef5e721c9cf4a6fd32bd167a0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>

41 files changed, 81 insertions, 81 deletions

diff --git a/src/widgets/widgets/qabstractbutton.h b/src/widgets/widgets/qabstractbutton.h
index 4b397e2396..5f3e82a2e6 100644
--- a/src/widgets/widgets/qabstractbutton.h
+++ b/src/widgets/widgets/qabstractbutton.h
@@ -63,7 +63,7 @@ class Q_WIDGETS_EXPORT QAbstractButton : public QWidget
     Q_PROPERTY(bool down READ isDown WRITE setDown DESIGNABLE false)
 
 public:
-    explicit QAbstractButton(QWidget* parent=0);
+    explicit QAbstractButton(QWidget *parent = Q_NULLPTR);
     ~QAbstractButton();
 
     void setText(const QString &text);
@@ -135,7 +135,7 @@ protected:
 
 
 protected:
-    QAbstractButton(QAbstractButtonPrivate &dd, QWidget* parent = 0);
+    QAbstractButton(QAbstractButtonPrivate &dd, QWidget* parent = Q_NULLPTR);
 
 private:
     Q_DECLARE_PRIVATE(QAbstractButton)
diff --git a/src/widgets/widgets/qabstractscrollarea.h b/src/widgets/widgets/qabstractscrollarea.h
index 13dafd547b..8bc32b1c78 100644
--- a/src/widgets/widgets/qabstractscrollarea.h
+++ b/src/widgets/widgets/qabstractscrollarea.h
@@ -54,7 +54,7 @@ class Q_WIDGETS_EXPORT QAbstractScrollArea : public QFrame
     Q_PROPERTY(SizeAdjustPolicy sizeAdjustPolicy READ sizeAdjustPolicy WRITE setSizeAdjustPolicy)
 
 public:
-    explicit QAbstractScrollArea(QWidget* parent=0);
+    explicit QAbstractScrollArea(QWidget *parent = Q_NULLPTR);
     ~QAbstractScrollArea();
 
     enum SizeAdjustPolicy {
@@ -94,7 +94,7 @@ public:
     void setSizeAdjustPolicy(SizeAdjustPolicy policy);
 
 protected:
-    QAbstractScrollArea(QAbstractScrollAreaPrivate &dd, QWidget *parent = 0);
+    QAbstractScrollArea(QAbstractScrollAreaPrivate &dd, QWidget *parent = Q_NULLPTR);
     void setViewportMargins(int left, int top, int right, int bottom);
     void setViewportMargins(const QMargins &margins);
     QMargins viewportMargins() const;
diff --git a/src/widgets/widgets/qabstractslider.h b/src/widgets/widgets/qabstractslider.h
index 2f649e3d3d..6faca5ea3c 100644
--- a/src/widgets/widgets/qabstractslider.h
+++ b/src/widgets/widgets/qabstractslider.h
@@ -58,7 +58,7 @@ class Q_WIDGETS_EXPORT QAbstractSlider : public QWidget
     Q_PROPERTY(bool sliderDown READ isSliderDown WRITE setSliderDown DESIGNABLE false)
 
 public:
-    explicit QAbstractSlider(QWidget *parent=0);
+    explicit QAbstractSlider(QWidget *parent = Q_NULLPTR);
     ~QAbstractSlider();
 
     Qt::Orientation orientation() const;
@@ -144,7 +144,7 @@ protected:
 
 
 protected:
-    QAbstractSlider(QAbstractSliderPrivate &dd, QWidget *parent=0);
+    QAbstractSlider(QAbstractSliderPrivate &dd, QWidget *parent = Q_NULLPTR);
 
 private:
     Q_DISABLE_COPY(QAbstractSlider)
diff --git a/src/widgets/widgets/qabstractspinbox.h b/src/widgets/widgets/qabstractspinbox.h
index a80a89c894..046036b9a8 100644
--- a/src/widgets/widgets/qabstractspinbox.h
+++ b/src/widgets/widgets/qabstractspinbox.h
@@ -64,7 +64,7 @@ class Q_WIDGETS_EXPORT QAbstractSpinBox : public QWidget
     Q_PROPERTY(bool keyboardTracking READ keyboardTracking WRITE setKeyboardTracking)
     Q_PROPERTY(bool showGroupSeparator READ isGroupSeparatorShown WRITE setGroupSeparatorShown)
 public:
-    explicit QAbstractSpinBox(QWidget *parent = 0);
+    explicit QAbstractSpinBox(QWidget *parent = Q_NULLPTR);
     ~QAbstractSpinBox();
 
     enum StepEnabledFlag { StepNone = 0x00, StepUpEnabled = 0x01,
@@ -154,7 +154,7 @@ protected:
 Q_SIGNALS:
     void editingFinished();
 protected:
-    QAbstractSpinBox(QAbstractSpinBoxPrivate &dd, QWidget *parent = 0);
+    QAbstractSpinBox(QAbstractSpinBoxPrivate &dd, QWidget *parent = Q_NULLPTR);
 
 private:
     Q_PRIVATE_SLOT(d_func(), void _q_editorTextChanged(const QString &))
diff --git a/src/widgets/widgets/qbuttongroup.h b/src/widgets/widgets/qbuttongroup.h
index 01de03ac84..ba4f8e26c1 100644
--- a/src/widgets/widgets/qbuttongroup.h
+++ b/src/widgets/widgets/qbuttongroup.h
@@ -51,7 +51,7 @@ class Q_WIDGETS_EXPORT QButtonGroup : public QObject
 
     Q_PROPERTY(bool exclusive READ exclusive WRITE setExclusive)
 public:
-    explicit QButtonGroup(QObject *parent = 0);
+    explicit QButtonGroup(QObject *parent = Q_NULLPTR);
     ~QButtonGroup();
 
     void setExclusive(bool);
diff --git a/src/widgets/widgets/qcalendarwidget.h b/src/widgets/widgets/qcalendarwidget.h
index c456cc2161..df54985351 100644
--- a/src/widgets/widgets/qcalendarwidget.h
+++ b/src/widgets/widgets/qcalendarwidget.h
@@ -83,7 +83,7 @@ public:
     };
     Q_ENUM(SelectionMode)
 
-    explicit QCalendarWidget(QWidget *parent = 0);
+    explicit QCalendarWidget(QWidget *parent = Q_NULLPTR);
     ~QCalendarWidget();
 
     virtual QSize sizeHint() const Q_DECL_OVERRIDE;
diff --git a/src/widgets/widgets/qcheckbox.h b/src/widgets/widgets/qcheckbox.h
index b614659f02..61d03eb8e6 100644
--- a/src/widgets/widgets/qcheckbox.h
+++ b/src/widgets/widgets/qcheckbox.h
@@ -49,8 +49,8 @@ class Q_WIDGETS_EXPORT QCheckBox : public QAbstractButton
     Q_PROPERTY(bool tristate READ isTristate WRITE setTristate)
 
 public:
-    explicit QCheckBox(QWidget *parent=0);
-    explicit QCheckBox(const QString &text, QWidget *parent=0);
+    explicit QCheckBox(QWidget *parent = Q_NULLPTR);
+    explicit QCheckBox(const QString &text, QWidget *parent = Q_NULLPTR);
     ~QCheckBox();
 
     QSize sizeHint() const Q_DECL_OVERRIDE;
diff --git a/src/widgets/widgets/qcombobox.h b/src/widgets/widgets/qcombobox.h
index ae35f7a89a..3182a0a3aa 100644
--- a/src/widgets/widgets/qcombobox.h
+++ b/src/widgets/widgets/qcombobox.h
@@ -74,7 +74,7 @@ class Q_WIDGETS_EXPORT QComboBox : public QWidget
     Q_PROPERTY(int modelColumn READ modelColumn WRITE setModelColumn)
 
 public:
-    explicit QComboBox(QWidget *parent = 0);
+    explicit QComboBox(QWidget *parent = Q_NULLPTR);
     ~QComboBox();
 
     int maxVisibleItems() const;
diff --git a/src/widgets/widgets/qcommandlinkbutton.h b/src/widgets/widgets/qcommandlinkbutton.h
index 486c48af5d..9ddb14270d 100644
--- a/src/widgets/widgets/qcommandlinkbutton.h
+++ b/src/widgets/widgets/qcommandlinkbutton.h
@@ -49,9 +49,9 @@ class Q_WIDGETS_EXPORT QCommandLinkButton: public QPushButton
     Q_PROPERTY(bool flat READ isFlat WRITE setFlat DESIGNABLE false)
 
 public:
-    explicit QCommandLinkButton(QWidget *parent=0);
-    explicit QCommandLinkButton(const QString &text, QWidget *parent=0);
-    explicit QCommandLinkButton(const QString &text, const QString &description, QWidget *parent=0);
+    explicit QCommandLinkButton(QWidget *parent = Q_NULLPTR);
+    explicit QCommandLinkButton(const QString &text, QWidget *parent = Q_NULLPTR);
+    explicit QCommandLinkButton(const QString &text, const QString &description, QWidget *parent = Q_NULLPTR);
     ~QCommandLinkButton();
 
     QString description() const;
diff --git a/src/widgets/widgets/qdatetimeedit.h b/src/widgets/widgets/qdatetimeedit.h
index 4e77713fd0..829ce205be 100644
--- a/src/widgets/widgets/qdatetimeedit.h
+++ b/src/widgets/widgets/qdatetimeedit.h
@@ -86,10 +86,10 @@ public:
 
     Q_DECLARE_FLAGS(Sections, Section)
 
-    explicit QDateTimeEdit(QWidget *parent = 0);
-    explicit QDateTimeEdit(const QDateTime &dt, QWidget *parent = 0);
-    explicit QDateTimeEdit(const QDate &d, QWidget *parent = 0);
-    explicit QDateTimeEdit(const QTime &t, QWidget *parent = 0);
+    explicit QDateTimeEdit(QWidget *parent = Q_NULLPTR);
+    explicit QDateTimeEdit(const QDateTime &dt, QWidget *parent = Q_NULLPTR);
+    explicit QDateTimeEdit(const QDate &d, QWidget *parent = Q_NULLPTR);
+    explicit QDateTimeEdit(const QTime &t, QWidget *parent = Q_NULLPTR);
     ~QDateTimeEdit();
 
     QDateTime dateTime() const;
@@ -185,7 +185,7 @@ protected:
     virtual void paintEvent(QPaintEvent *event);
     void initStyleOption(QStyleOptionSpinBox *option) const;
 
-    QDateTimeEdit(const QVariant &val, QVariant::Type parserType, QWidget *parent = 0);
+    QDateTimeEdit(const QVariant &val, QVariant::Type parserType, QWidget *parent = Q_NULLPTR);
 private:
     Q_DECLARE_PRIVATE(QDateTimeEdit)
     Q_DISABLE_COPY(QDateTimeEdit)
@@ -198,8 +198,8 @@ class Q_WIDGETS_EXPORT QTimeEdit : public QDateTimeEdit
     Q_OBJECT
     Q_PROPERTY(QTime time READ time WRITE setTime NOTIFY userTimeChanged USER true)
 public:
-    explicit QTimeEdit(QWidget *parent = 0);
-    explicit QTimeEdit(const QTime &time, QWidget *parent = 0);
+    explicit QTimeEdit(QWidget *parent = Q_NULLPTR);
+    explicit QTimeEdit(const QTime &time, QWidget *parent = Q_NULLPTR);
     ~QTimeEdit();
 
 Q_SIGNALS:
@@ -211,8 +211,8 @@ class Q_WIDGETS_EXPORT QDateEdit : public QDateTimeEdit
     Q_OBJECT
     Q_PROPERTY(QDate date READ date WRITE setDate NOTIFY userDateChanged USER true)
 public:
-    explicit QDateEdit(QWidget *parent = 0);
-    explicit QDateEdit(const QDate &date, QWidget *parent = 0);
+    explicit QDateEdit(QWidget *parent = Q_NULLPTR);
+    explicit QDateEdit(const QDate &date, QWidget *parent = Q_NULLPTR);
     ~QDateEdit();
 
 Q_SIGNALS:
diff --git a/src/widgets/widgets/qdial.h b/src/widgets/widgets/qdial.h
index 7e01aefce3..cb69e02301 100644
--- a/src/widgets/widgets/qdial.h
+++ b/src/widgets/widgets/qdial.h
@@ -54,7 +54,7 @@ class Q_WIDGETS_EXPORT QDial: public QAbstractSlider
     Q_PROPERTY(qreal notchTarget READ notchTarget WRITE setNotchTarget)
     Q_PROPERTY(bool notchesVisible READ notchesVisible WRITE setNotchesVisible)
 public:
-    explicit QDial(QWidget *parent = 0);
+    explicit QDial(QWidget *parent = Q_NULLPTR);
 
     ~QDial();
 
diff --git a/src/widgets/widgets/qdialogbuttonbox.h b/src/widgets/widgets/qdialogbuttonbox.h
index 02960b5b79..83c1fd66fd 100644
--- a/src/widgets/widgets/qdialogbuttonbox.h
+++ b/src/widgets/widgets/qdialogbuttonbox.h
@@ -106,11 +106,11 @@ public:
         GnomeLayout
     };
 
-    QDialogButtonBox(QWidget *parent = 0);
-    QDialogButtonBox(Qt::Orientation orientation, QWidget *parent = 0);
-    explicit QDialogButtonBox(StandardButtons buttons, QWidget *parent = 0);
+    QDialogButtonBox(QWidget *parent = Q_NULLPTR);
+    QDialogButtonBox(Qt::Orientation orientation, QWidget *parent = Q_NULLPTR);
+    explicit QDialogButtonBox(StandardButtons buttons, QWidget *parent = Q_NULLPTR);
     QDialogButtonBox(StandardButtons buttons, Qt::Orientation orientation,
-                     QWidget *parent = 0);
+                     QWidget *parent = Q_NULLPTR);
     ~QDialogButtonBox();
 
     void setOrientation(Qt::Orientation orientation);
diff --git a/src/widgets/widgets/qfocusframe.h b/src/widgets/widgets/qfocusframe.h
index f976ba9827..bbd639c2f9 100644
--- a/src/widgets/widgets/qfocusframe.h
+++ b/src/widgets/widgets/qfocusframe.h
@@ -46,7 +46,7 @@ class Q_WIDGETS_EXPORT QFocusFrame : public QWidget
 {
     Q_OBJECT
 public:
-    QFocusFrame(QWidget *parent=0);
+    QFocusFrame(QWidget *parent = Q_NULLPTR);
     ~QFocusFrame();
 
     void setWidget(QWidget *widget);
diff --git a/src/widgets/widgets/qfontcombobox.h b/src/widgets/widgets/qfontcombobox.h
index 0c8cf5d58d..412acd041e 100644
--- a/src/widgets/widgets/qfontcombobox.h
+++ b/src/widgets/widgets/qfontcombobox.h
@@ -53,7 +53,7 @@ class Q_WIDGETS_EXPORT QFontComboBox : public QComboBox
     Q_PROPERTY(QFont currentFont READ currentFont WRITE setCurrentFont NOTIFY currentFontChanged)
 
 public:
-    explicit QFontComboBox(QWidget *parent = 0);
+    explicit QFontComboBox(QWidget *parent = Q_NULLPTR);
     ~QFontComboBox();
 
     void setWritingSystem(QFontDatabase::WritingSystem);
diff --git a/src/widgets/widgets/qgroupbox.h b/src/widgets/widgets/qgroupbox.h
index 8100fadff4..57ebdce8dd 100644
--- a/src/widgets/widgets/qgroupbox.h
+++ b/src/widgets/widgets/qgroupbox.h
@@ -53,8 +53,8 @@ class Q_WIDGETS_EXPORT QGroupBox : public QWidget
     Q_PROPERTY(bool checkable READ isCheckable WRITE setCheckable)
     Q_PROPERTY(bool checked READ isChecked WRITE setChecked DESIGNABLE isCheckable NOTIFY toggled USER true)
 public:
-    explicit QGroupBox(QWidget* parent=0);
-    explicit QGroupBox(const QString &title, QWidget* parent=0);
+    explicit QGroupBox(QWidget *parent = Q_NULLPTR);
+    explicit QGroupBox(const QString &title, QWidget *parent = Q_NULLPTR);
     ~QGroupBox();
 
     QString title() const;
diff --git a/src/widgets/widgets/qkeysequenceedit.h b/src/widgets/widgets/qkeysequenceedit.h
index 1887a40bfc..ad60bcc513 100644
--- a/src/widgets/widgets/qkeysequenceedit.h
+++ b/src/widgets/widgets/qkeysequenceedit.h
@@ -48,8 +48,8 @@ class Q_WIDGETS_EXPORT QKeySequenceEdit : public QWidget
     Q_PROPERTY(QKeySequence keySequence READ keySequence WRITE setKeySequence NOTIFY keySequenceChanged USER true)
 
 public:
-    explicit QKeySequenceEdit(QWidget *parent = 0);
-    explicit QKeySequenceEdit(const QKeySequence &keySequence, QWidget *parent = 0);
+    explicit QKeySequenceEdit(QWidget *parent = Q_NULLPTR);
+    explicit QKeySequenceEdit(const QKeySequence &keySequence, QWidget *parent = Q_NULLPTR);
     ~QKeySequenceEdit();
 
     QKeySequence keySequence() const;
diff --git a/src/widgets/widgets/qlcdnumber.h b/src/widgets/widgets/qlcdnumber.h
index d93edc75ca..9a7904a8bb 100644
--- a/src/widgets/widgets/qlcdnumber.h
+++ b/src/widgets/widgets/qlcdnumber.h
@@ -53,8 +53,8 @@ class Q_WIDGETS_EXPORT QLCDNumber : public QFrame // LCD number widget
     Q_PROPERTY(int intValue READ intValue WRITE display)
 
 public:
-    explicit QLCDNumber(QWidget* parent = 0);
-    explicit QLCDNumber(uint numDigits, QWidget* parent = 0);
+    explicit QLCDNumber(QWidget* parent = Q_NULLPTR);
+    explicit QLCDNumber(uint numDigits, QWidget* parent = Q_NULLPTR);
     ~QLCDNumber();
 
     enum Mode {
diff --git a/src/widgets/widgets/qlineedit.h b/src/widgets/widgets/qlineedit.h
index e006f1c0d8..ac192f0da8 100644
--- a/src/widgets/widgets/qlineedit.h
+++ b/src/widgets/widgets/qlineedit.h
@@ -84,8 +84,8 @@ public:
     };
     Q_ENUM(ActionPosition)
 
-    explicit QLineEdit(QWidget* parent=0);
-    explicit QLineEdit(const QString &, QWidget* parent=0);
+    explicit QLineEdit(QWidget *parent = Q_NULLPTR);
+    explicit QLineEdit(const QString &, QWidget *parent = Q_NULLPTR);
     ~QLineEdit();
 
     QString text() const;
diff --git a/src/widgets/widgets/qmaccocoaviewcontainer_mac.h b/src/widgets/widgets/qmaccocoaviewcontainer_mac.h
index 5920c1f8bf..a27d8f8690 100644
--- a/src/widgets/widgets/qmaccocoaviewcontainer_mac.h
+++ b/src/widgets/widgets/qmaccocoaviewcontainer_mac.h
@@ -45,7 +45,7 @@ class Q_WIDGETS_EXPORT QMacCocoaViewContainer : public QWidget
 {
     Q_OBJECT
 public:
-    QMacCocoaViewContainer(NSView *cocoaViewToWrap, QWidget *parent = 0);
+    QMacCocoaViewContainer(NSView *cocoaViewToWrap, QWidget *parent = Q_NULLPTR);
     virtual ~QMacCocoaViewContainer();
 
     void setCocoaView(NSView *view);
diff --git a/src/widgets/widgets/qmacnativewidget_mac.h b/src/widgets/widgets/qmacnativewidget_mac.h
index 761e55656b..5e82872faa 100644
--- a/src/widgets/widgets/qmacnativewidget_mac.h
+++ b/src/widgets/widgets/qmacnativewidget_mac.h
@@ -45,7 +45,7 @@ class Q_WIDGETS_EXPORT QMacNativeWidget : public QWidget
 {
     Q_OBJECT
 public:
-    QMacNativeWidget(NSView *parentView = 0);
+    QMacNativeWidget(NSView *parentView = Q_NULLPTR);
     ~QMacNativeWidget();
 
     QSize sizeHint() const;
diff --git a/src/widgets/widgets/qmdiarea.h b/src/widgets/widgets/qmdiarea.h
index f1361fffc6..e05535b2af 100644
--- a/src/widgets/widgets/qmdiarea.h
+++ b/src/widgets/widgets/qmdiarea.h
@@ -79,7 +79,7 @@ public:
     };
     Q_ENUM(ViewMode)
 
-    QMdiArea(QWidget *parent = 0);
+    QMdiArea(QWidget *parent = Q_NULLPTR);
     ~QMdiArea();
 
     QSize sizeHint() const Q_DECL_OVERRIDE;
diff --git a/src/widgets/widgets/qmenu.h b/src/widgets/widgets/qmenu.h
index 21e1432d2a..6bbe54186e 100644
--- a/src/widgets/widgets/qmenu.h
+++ b/src/widgets/widgets/qmenu.h
@@ -68,8 +68,8 @@ private:
     Q_PROPERTY(bool toolTipsVisible READ toolTipsVisible WRITE setToolTipsVisible)
 
 public:
-    explicit QMenu(QWidget *parent = 0);
-    explicit QMenu(const QString &title, QWidget *parent = 0);
+    explicit QMenu(QWidget *parent = Q_NULLPTR);
+    explicit QMenu(const QString &title, QWidget *parent = Q_NULLPTR);
     ~QMenu();
 
     using QWidget::addAction;
@@ -173,14 +173,14 @@ public:
     void setActiveAction(QAction *act);
     QAction *activeAction() const;
 
-    void popup(const QPoint &pos, QAction *at=0);
+    void popup(const QPoint &pos, QAction *at = Q_NULLPTR);
     QAction *exec();
-    QAction *exec(const QPoint &pos, QAction *at=0);
+    QAction *exec(const QPoint &pos, QAction *at = Q_NULLPTR);
 
 #if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
-    static QAction *exec(const QList<QAction *> &actions, const QPoint &pos, QAction *at = 0, QWidget *parent = 0);
+    static QAction *exec(const QList<QAction *> &actions, const QPoint &pos, QAction *at = Q_NULLPTR, QWidget *parent = Q_NULLPTR);
 #else
-    static QAction *exec(QList<QAction*> actions, const QPoint &pos, QAction *at=0, QWidget *parent=0);
+    static QAction *exec(QList<QAction*> actions, const QPoint &pos, QAction *at = Q_NULLPTR, QWidget *parent = Q_NULLPTR);
 #endif
 
     QSize sizeHint() const Q_DECL_OVERRIDE;
@@ -255,7 +255,7 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_platformMenuAboutToShow())
 
 protected:
-    QMenu(QMenuPrivate &dd, QWidget* parent = 0);
+    QMenu(QMenuPrivate &dd, QWidget* parent = Q_NULLPTR);
 
 private:
     Q_DISABLE_COPY(QMenu)
diff --git a/src/widgets/widgets/qmenubar.h b/src/widgets/widgets/qmenubar.h
index 461dec8a94..3b3980c860 100644
--- a/src/widgets/widgets/qmenubar.h
+++ b/src/widgets/widgets/qmenubar.h
@@ -54,7 +54,7 @@ class Q_WIDGETS_EXPORT QMenuBar : public QWidget
     Q_PROPERTY(bool nativeMenuBar READ isNativeMenuBar WRITE setNativeMenuBar)
 
 public:
-    explicit QMenuBar(QWidget *parent = 0);
+    explicit QMenuBar(QWidget *parent = Q_NULLPTR);
     ~QMenuBar();
 
     using QWidget::addAction;
diff --git a/src/widgets/widgets/qplaintextedit.h b/src/widgets/widgets/qplaintextedit.h
index 69bd2ab647..fc378c6ab9 100644
--- a/src/widgets/widgets/qplaintextedit.h
+++ b/src/widgets/widgets/qplaintextedit.h
@@ -82,8 +82,8 @@ public:
     };
     Q_ENUM(LineWrapMode)
 
-    explicit QPlainTextEdit(QWidget *parent = 0);
-    explicit QPlainTextEdit(const QString &text, QWidget *parent = 0);
+    explicit QPlainTextEdit(QWidget *parent = Q_NULLPTR);
+    explicit QPlainTextEdit(const QString &text, QWidget *parent = Q_NULLPTR);
     virtual ~QPlainTextEdit();
 
     void setDocument(QTextDocument *document);
diff --git a/src/widgets/widgets/qprogressbar.h b/src/widgets/widgets/qprogressbar.h
index 0c3200f82c..e17e01c17b 100644
--- a/src/widgets/widgets/qprogressbar.h
+++ b/src/widgets/widgets/qprogressbar.h
@@ -62,7 +62,7 @@ public:
     enum Direction { TopToBottom, BottomToTop };
     Q_ENUM(Direction)
 
-    explicit QProgressBar(QWidget *parent = 0);
+    explicit QProgressBar(QWidget *parent = Q_NULLPTR);
     ~QProgressBar();
 
     int minimum() const;
diff --git a/src/widgets/widgets/qpushbutton.h b/src/widgets/widgets/qpushbutton.h
index 2521c0982e..3db12be380 100644
--- a/src/widgets/widgets/qpushbutton.h
+++ b/src/widgets/widgets/qpushbutton.h
@@ -52,9 +52,9 @@ class Q_WIDGETS_EXPORT QPushButton : public QAbstractButton
     Q_PROPERTY(bool flat READ isFlat WRITE setFlat)
 
 public:
-    explicit QPushButton(QWidget *parent=0);
-    explicit QPushButton(const QString &text, QWidget *parent=0);
-    QPushButton(const QIcon& icon, const QString &text, QWidget *parent=0);
+    explicit QPushButton(QWidget *parent = Q_NULLPTR);
+    explicit QPushButton(const QString &text, QWidget *parent = Q_NULLPTR);
+    QPushButton(const QIcon& icon, const QString &text, QWidget *parent = Q_NULLPTR);
     ~QPushButton();
 
     QSize sizeHint() const Q_DECL_OVERRIDE;
@@ -88,7 +88,7 @@ protected:
     void focusInEvent(QFocusEvent *) Q_DECL_OVERRIDE;
     void focusOutEvent(QFocusEvent *) Q_DECL_OVERRIDE;
     void initStyleOption(QStyleOptionButton *option) const;
-    QPushButton(QPushButtonPrivate &dd, QWidget* parent = 0);
+    QPushButton(QPushButtonPrivate &dd, QWidget* parent = Q_NULLPTR);
 
 public:
 
diff --git a/src/widgets/widgets/qradiobutton.h b/src/widgets/widgets/qradiobutton.h
index f323f5af99..df0b1051bf 100644
--- a/src/widgets/widgets/qradiobutton.h
+++ b/src/widgets/widgets/qradiobutton.h
@@ -47,8 +47,8 @@ class Q_WIDGETS_EXPORT QRadioButton : public QAbstractButton
     Q_OBJECT
 
 public:
-    explicit QRadioButton(QWidget *parent=0);
-    explicit QRadioButton(const QString &text, QWidget *parent=0);
+    explicit QRadioButton(QWidget *parent = Q_NULLPTR);
+    explicit QRadioButton(const QString &text, QWidget *parent = Q_NULLPTR);
     ~QRadioButton();
 
     QSize sizeHint() const Q_DECL_OVERRIDE;
diff --git a/src/widgets/widgets/qrubberband.h b/src/widgets/widgets/qrubberband.h
index 3ff6eb47fa..b0dc14ed98 100644
--- a/src/widgets/widgets/qrubberband.h
+++ b/src/widgets/widgets/qrubberband.h
@@ -50,7 +50,7 @@ class Q_WIDGETS_EXPORT QRubberBand : public QWidget
 
 public:
     enum Shape { Line, Rectangle };
-    explicit QRubberBand(Shape, QWidget * =0);
+    explicit QRubberBand(Shape, QWidget * = Q_NULLPTR);
     ~QRubberBand();
 
     Shape shape() const;
diff --git a/src/widgets/widgets/qscrollarea.h b/src/widgets/widgets/qscrollarea.h
index cafb1ec6de..1658236034 100644
--- a/src/widgets/widgets/qscrollarea.h
+++ b/src/widgets/widgets/qscrollarea.h
@@ -50,7 +50,7 @@ class Q_WIDGETS_EXPORT QScrollArea : public QAbstractScrollArea
     Q_PROPERTY(Qt::Alignment alignment READ alignment WRITE setAlignment)
 
 public:
-    explicit QScrollArea(QWidget* parent=0);
+    explicit QScrollArea(QWidget *parent = Q_NULLPTR);
     ~QScrollArea();
 
     QWidget *widget() const;
@@ -71,7 +71,7 @@ public:
     void ensureWidgetVisible(QWidget *childWidget, int xmargin = 50, int ymargin = 50);
 
 protected:
-    QScrollArea(QScrollAreaPrivate &dd, QWidget *parent = 0);
+    QScrollArea(QScrollAreaPrivate &dd, QWidget *parent = Q_NULLPTR);
     bool event(QEvent *) Q_DECL_OVERRIDE;
     bool eventFilter(QObject *, QEvent *) Q_DECL_OVERRIDE;
     void resizeEvent(QResizeEvent *) Q_DECL_OVERRIDE;
diff --git a/src/widgets/widgets/qscrollbar.h b/src/widgets/widgets/qscrollbar.h
index 5934469045..4af5fb4a55 100644
--- a/src/widgets/widgets/qscrollbar.h
+++ b/src/widgets/widgets/qscrollbar.h
@@ -49,8 +49,8 @@ class Q_WIDGETS_EXPORT QScrollBar : public QAbstractSlider
 {
     Q_OBJECT
 public:
-    explicit QScrollBar(QWidget *parent=0);
-    explicit QScrollBar(Qt::Orientation, QWidget *parent=0);
+    explicit QScrollBar(QWidget *parent = Q_NULLPTR);
+    explicit QScrollBar(Qt::Orientation, QWidget *parent = Q_NULLPTR);
     ~QScrollBar();
 
     QSize sizeHint() const Q_DECL_OVERRIDE;
diff --git a/src/widgets/widgets/qslider.h b/src/widgets/widgets/qslider.h
index 3a528382a7..801a684fdf 100644
--- a/src/widgets/widgets/qslider.h
+++ b/src/widgets/widgets/qslider.h
@@ -61,8 +61,8 @@ public:
     };
     Q_ENUM(TickPosition)
 
-    explicit QSlider(QWidget *parent = 0);
-    explicit QSlider(Qt::Orientation orientation, QWidget *parent = 0);
+    explicit QSlider(QWidget *parent = Q_NULLPTR);
+    explicit QSlider(Qt::Orientation orientation, QWidget *parent = Q_NULLPTR);
 
     ~QSlider();
 
diff --git a/src/widgets/widgets/qspinbox.h b/src/widgets/widgets/qspinbox.h
index 606206d4f0..066fe88562 100644
--- a/src/widgets/widgets/qspinbox.h
+++ b/src/widgets/widgets/qspinbox.h
@@ -56,7 +56,7 @@ class Q_WIDGETS_EXPORT QSpinBox : public QAbstractSpinBox
     Q_PROPERTY(int displayIntegerBase READ displayIntegerBase WRITE setDisplayIntegerBase)
 
 public:
-    explicit QSpinBox(QWidget *parent = 0);
+    explicit QSpinBox(QWidget *parent = Q_NULLPTR);
     ~QSpinBox();
 
     int value() const;
@@ -117,7 +117,7 @@ class Q_WIDGETS_EXPORT QDoubleSpinBox : public QAbstractSpinBox
     Q_PROPERTY(double singleStep READ singleStep WRITE setSingleStep)
     Q_PROPERTY(double value READ value WRITE setValue NOTIFY valueChanged USER true)
 public:
-    explicit QDoubleSpinBox(QWidget *parent = 0);
+    explicit QDoubleSpinBox(QWidget *parent = Q_NULLPTR);
     ~QDoubleSpinBox();
 
     double value() const;
diff --git a/src/widgets/widgets/qsplitter.h b/src/widgets/widgets/qsplitter.h
index 4da92acd22..84010c236b 100644
--- a/src/widgets/widgets/qsplitter.h
+++ b/src/widgets/widgets/qsplitter.h
@@ -58,8 +58,8 @@ class Q_WIDGETS_EXPORT QSplitter : public QFrame
     Q_PROPERTY(bool childrenCollapsible READ childrenCollapsible WRITE setChildrenCollapsible)
 
 public:
-    explicit QSplitter(QWidget* parent = 0);
-    explicit QSplitter(Qt::Orientation, QWidget* parent = 0);
+    explicit QSplitter(QWidget* parent = Q_NULLPTR);
+    explicit QSplitter(Qt::Orientation, QWidget* parent = Q_NULLPTR);
     ~QSplitter();
 
     void addWidget(QWidget *widget);
diff --git a/src/widgets/widgets/qstackedwidget.h b/src/widgets/widgets/qstackedwidget.h
index 4267d8241f..9fcdf80833 100644
--- a/src/widgets/widgets/qstackedwidget.h
+++ b/src/widgets/widgets/qstackedwidget.h
@@ -50,7 +50,7 @@ class Q_WIDGETS_EXPORT QStackedWidget : public QFrame
     Q_PROPERTY(int currentIndex READ currentIndex WRITE setCurrentIndex NOTIFY currentChanged)
     Q_PROPERTY(int count READ count)
 public:
-    explicit QStackedWidget(QWidget *parent=0);
+    explicit QStackedWidget(QWidget *parent = Q_NULLPTR);
     ~QStackedWidget();
 
     int addWidget(QWidget *w);
diff --git a/src/widgets/widgets/qstatusbar.h b/src/widgets/widgets/qstatusbar.h
index 42248d7958..92785aa4c4 100644
--- a/src/widgets/widgets/qstatusbar.h
+++ b/src/widgets/widgets/qstatusbar.h
@@ -50,7 +50,7 @@ class Q_WIDGETS_EXPORT QStatusBar: public QWidget
     Q_PROPERTY(bool sizeGripEnabled READ isSizeGripEnabled WRITE setSizeGripEnabled)
 
 public:
-    explicit QStatusBar(QWidget* parent=0);
+    explicit QStatusBar(QWidget *parent = Q_NULLPTR);
     virtual ~QStatusBar();
 
     void addWidget(QWidget *widget, int stretch = 0);
diff --git a/src/widgets/widgets/qtabbar.h b/src/widgets/widgets/qtabbar.h
index 6d8bdb0c86..94a83142b0 100644
--- a/src/widgets/widgets/qtabbar.h
+++ b/src/widgets/widgets/qtabbar.h
@@ -65,7 +65,7 @@ class Q_WIDGETS_EXPORT QTabBar: public QWidget
     Q_PROPERTY(bool changeCurrentOnDrag READ changeCurrentOnDrag WRITE setChangeCurrentOnDrag)
 
 public:
-    explicit QTabBar(QWidget* parent=0);
+    explicit QTabBar(QWidget *parent = Q_NULLPTR);
     ~QTabBar();
 
     enum Shape { RoundedNorth, RoundedSouth, RoundedWest, RoundedEast,
diff --git a/src/widgets/widgets/qtabwidget.h b/src/widgets/widgets/qtabwidget.h
index 702563127d..f12d584475 100644
--- a/src/widgets/widgets/qtabwidget.h
+++ b/src/widgets/widgets/qtabwidget.h
@@ -62,7 +62,7 @@ class Q_WIDGETS_EXPORT QTabWidget : public QWidget
     Q_PROPERTY(bool tabBarAutoHide READ tabBarAutoHide WRITE setTabBarAutoHide)
 
 public:
-    explicit QTabWidget(QWidget *parent = 0);
+    explicit QTabWidget(QWidget *parent = Q_NULLPTR);
     ~QTabWidget();
 
     int addTab(QWidget *widget, const QString &);
diff --git a/src/widgets/widgets/qtextbrowser.h b/src/widgets/widgets/qtextbrowser.h
index 4d4d9f4880..339814e948 100644
--- a/src/widgets/widgets/qtextbrowser.h
+++ b/src/widgets/widgets/qtextbrowser.h
@@ -57,7 +57,7 @@ class Q_WIDGETS_EXPORT QTextBrowser : public QTextEdit
     Q_PROPERTY(bool openLinks READ openLinks WRITE setOpenLinks)
 
 public:
-    explicit QTextBrowser(QWidget* parent = 0);
+    explicit QTextBrowser(QWidget* parent = Q_NULLPTR);
     virtual ~QTextBrowser();
 
     QUrl source() const;
diff --git a/src/widgets/widgets/qtextedit.h b/src/widgets/widgets/qtextedit.h
index 689f45bea9..8519bf1163 100644
--- a/src/widgets/widgets/qtextedit.h
+++ b/src/widgets/widgets/qtextedit.h
@@ -94,8 +94,8 @@ public:
 
     Q_DECLARE_FLAGS(AutoFormatting, AutoFormattingFlag)
 
-    explicit QTextEdit(QWidget *parent = 0);
-    explicit QTextEdit(const QString &text, QWidget *parent = 0);
+    explicit QTextEdit(QWidget *parent = Q_NULLPTR);
+    explicit QTextEdit(const QString &text, QWidget *parent = Q_NULLPTR);
     virtual ~QTextEdit();
 
     void setDocument(QTextDocument *document);
diff --git a/src/widgets/widgets/qtoolbar.h b/src/widgets/widgets/qtoolbar.h
index f4ed13d399..9eeb7ccd71 100644
--- a/src/widgets/widgets/qtoolbar.h
+++ b/src/widgets/widgets/qtoolbar.h
@@ -69,8 +69,8 @@ class Q_WIDGETS_EXPORT QToolBar : public QWidget
     Q_PROPERTY(bool floatable READ isFloatable WRITE setFloatable)
 
 public:
-    explicit QToolBar(const QString &title, QWidget *parent = 0);
-    explicit QToolBar(QWidget *parent = 0);
+    explicit QToolBar(const QString &title, QWidget *parent = Q_NULLPTR);
+    explicit QToolBar(QWidget *parent = Q_NULLPTR);
     ~QToolBar();
 
     void setMovable(bool movable);
diff --git a/src/widgets/widgets/qtoolbutton.h b/src/widgets/widgets/qtoolbutton.h
index 69ad032324..c76f58577b 100644
--- a/src/widgets/widgets/qtoolbutton.h
+++ b/src/widgets/widgets/qtoolbutton.h
@@ -64,7 +64,7 @@ public:
     };
     Q_ENUM(ToolButtonPopupMode)
 
-    explicit QToolButton(QWidget * parent=0);
+    explicit QToolButton(QWidget *parent = Q_NULLPTR);
     ~QToolButton();
 
     QSize sizeHint() const Q_DECL_OVERRIDE;