Add explicit and make public headers compile with -Wzero-as-null-pointer-constant

... or equivalent.

QtBase 5.6 headers already compile that way, so let the other
modules follow suit.

Added explicit where it was missing. This is not a source-
incompatible change, because code that breaks by this is
a bug. Let's not have this sitting around in an LTS.

Change-Id: I579e8714f94884dc555b673c9f85508f17cdc99d
Task-number: QTBUG-45291
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@theqtcompany.com>

33 files changed, 98 insertions, 98 deletions

diff --git a/src/datavisualization/axis/qabstract3daxis.h b/src/datavisualization/axis/qabstract3daxis.h
index e5b5dbcf..88153c3b 100644
--- a/src/datavisualization/axis/qabstract3daxis.h
+++ b/src/datavisualization/axis/qabstract3daxis.h
@@ -62,7 +62,7 @@ public:
     };
 
 protected:
-    explicit QAbstract3DAxis(QAbstract3DAxisPrivate *d, QObject *parent = 0);
+    explicit QAbstract3DAxis(QAbstract3DAxisPrivate *d, QObject *parent = Q_NULLPTR);
 
 public:
     virtual ~QAbstract3DAxis();
diff --git a/src/datavisualization/axis/qcategory3daxis.h b/src/datavisualization/axis/qcategory3daxis.h
index 994432ef..97fca13a 100644
--- a/src/datavisualization/axis/qcategory3daxis.h
+++ b/src/datavisualization/axis/qcategory3daxis.h
@@ -34,7 +34,7 @@ class QT_DATAVISUALIZATION_EXPORT QCategory3DAxis : public QAbstract3DAxis
     Q_PROPERTY(QStringList labels READ labels WRITE setLabels NOTIFY labelsChanged)
 
 public:
-    explicit QCategory3DAxis(QObject *parent = 0);
+    explicit QCategory3DAxis(QObject *parent = Q_NULLPTR);
     virtual ~QCategory3DAxis();
 
     void setLabels(const QStringList &labels);
diff --git a/src/datavisualization/axis/qlogvalue3daxisformatter.h b/src/datavisualization/axis/qlogvalue3daxisformatter.h
index ddbc8d50..d4d84b7c 100644
--- a/src/datavisualization/axis/qlogvalue3daxisformatter.h
+++ b/src/datavisualization/axis/qlogvalue3daxisformatter.h
@@ -37,9 +37,9 @@ class QT_DATAVISUALIZATION_EXPORT QLogValue3DAxisFormatter : public QValue3DAxis
     Q_PROPERTY(bool showEdgeLabels READ showEdgeLabels WRITE setShowEdgeLabels NOTIFY showEdgeLabelsChanged)
 
 protected:
-    explicit QLogValue3DAxisFormatter(QLogValue3DAxisFormatterPrivate *d, QObject *parent = 0);
+    explicit QLogValue3DAxisFormatter(QLogValue3DAxisFormatterPrivate *d, QObject *parent = Q_NULLPTR);
 public:
-    explicit QLogValue3DAxisFormatter(QObject *parent = 0);
+    explicit QLogValue3DAxisFormatter(QObject *parent = Q_NULLPTR);
     virtual ~QLogValue3DAxisFormatter();
 
     void setBase(qreal base);
diff --git a/src/datavisualization/axis/qvalue3daxis.h b/src/datavisualization/axis/qvalue3daxis.h
index 37076482..68467e3e 100644
--- a/src/datavisualization/axis/qvalue3daxis.h
+++ b/src/datavisualization/axis/qvalue3daxis.h
@@ -39,7 +39,7 @@ class QT_DATAVISUALIZATION_EXPORT QValue3DAxis : public QAbstract3DAxis
     Q_PROPERTY(bool reversed READ reversed WRITE setReversed NOTIFY reversedChanged REVISION 1)
 
 public:
-    explicit QValue3DAxis(QObject *parent = 0);
+    explicit QValue3DAxis(QObject *parent = Q_NULLPTR);
     virtual ~QValue3DAxis();
 
     void setSegmentCount(int count);
diff --git a/src/datavisualization/axis/qvalue3daxisformatter.h b/src/datavisualization/axis/qvalue3daxisformatter.h
index e9aaaa16..904fd137 100644
--- a/src/datavisualization/axis/qvalue3daxisformatter.h
+++ b/src/datavisualization/axis/qvalue3daxisformatter.h
@@ -38,9 +38,9 @@ class QT_DATAVISUALIZATION_EXPORT QValue3DAxisFormatter : public QObject
 {
     Q_OBJECT
 protected:
-    explicit QValue3DAxisFormatter(QValue3DAxisFormatterPrivate *d, QObject *parent = 0);
+    explicit QValue3DAxisFormatter(QValue3DAxisFormatterPrivate *d, QObject *parent = Q_NULLPTR);
 public:
-    explicit QValue3DAxisFormatter(QObject *parent = 0);
+    explicit QValue3DAxisFormatter(QObject *parent = Q_NULLPTR);
     virtual ~QValue3DAxisFormatter();
 
 protected:
diff --git a/src/datavisualization/data/qabstract3dseries.h b/src/datavisualization/data/qabstract3dseries.h
index 346fa026..c6d26d0a 100644
--- a/src/datavisualization/data/qabstract3dseries.h
+++ b/src/datavisualization/data/qabstract3dseries.h
@@ -80,7 +80,7 @@ public:
     };
 
 protected:
-    explicit QAbstract3DSeries(QAbstract3DSeriesPrivate *d, QObject *parent = 0);
+    explicit QAbstract3DSeries(QAbstract3DSeriesPrivate *d, QObject *parent = Q_NULLPTR);
 
 public:
     virtual ~QAbstract3DSeries();
diff --git a/src/datavisualization/data/qabstractdataproxy.h b/src/datavisualization/data/qabstractdataproxy.h
index 649628ba..c4388ad5 100644
--- a/src/datavisualization/data/qabstractdataproxy.h
+++ b/src/datavisualization/data/qabstractdataproxy.h
@@ -45,7 +45,7 @@ public:
     };
 
 protected:
-    explicit QAbstractDataProxy(QAbstractDataProxyPrivate *d, QObject *parent = 0);
+    explicit QAbstractDataProxy(QAbstractDataProxyPrivate *d, QObject *parent = Q_NULLPTR);
 
 public:
     virtual ~QAbstractDataProxy();
diff --git a/src/datavisualization/data/qbar3dseries.h b/src/datavisualization/data/qbar3dseries.h
index b9e08b0c..bca23e2f 100644
--- a/src/datavisualization/data/qbar3dseries.h
+++ b/src/datavisualization/data/qbar3dseries.h
@@ -38,8 +38,8 @@ class QT_DATAVISUALIZATION_EXPORT QBar3DSeries : public QAbstract3DSeries
     Q_PROPERTY(float meshAngle READ meshAngle WRITE setMeshAngle NOTIFY meshAngleChanged)
 
 public:
-    explicit QBar3DSeries(QObject *parent = 0);
-    explicit QBar3DSeries(QBarDataProxy *dataProxy, QObject *parent = 0);
+    explicit QBar3DSeries(QObject *parent = Q_NULLPTR);
+    explicit QBar3DSeries(QBarDataProxy *dataProxy, QObject *parent = Q_NULLPTR);
     virtual ~QBar3DSeries();
 
     void setDataProxy(QBarDataProxy *proxy);
diff --git a/src/datavisualization/data/qbardataproxy.h b/src/datavisualization/data/qbardataproxy.h
index aee38883..8db2fee0 100644
--- a/src/datavisualization/data/qbardataproxy.h
+++ b/src/datavisualization/data/qbardataproxy.h
@@ -47,7 +47,7 @@ class QT_DATAVISUALIZATION_EXPORT QBarDataProxy : public QAbstractDataProxy
     Q_PROPERTY(QStringList columnLabels READ columnLabels WRITE setColumnLabels NOTIFY columnLabelsChanged)
     Q_PROPERTY(QBar3DSeries *series READ series NOTIFY seriesChanged)
 public:
-    explicit QBarDataProxy(QObject *parent = 0);
+    explicit QBarDataProxy(QObject *parent = Q_NULLPTR);
     virtual ~QBarDataProxy();
 
     QBar3DSeries *series() const;
@@ -102,7 +102,7 @@ Q_SIGNALS:
     void seriesChanged(QBar3DSeries *series);
 
 protected:
-    explicit QBarDataProxy(QBarDataProxyPrivate *d, QObject *parent = 0);
+    explicit QBarDataProxy(QBarDataProxyPrivate *d, QObject *parent = Q_NULLPTR);
     QBarDataProxyPrivate *dptr();
     const QBarDataProxyPrivate *dptrc() const;
 
diff --git a/src/datavisualization/data/qcustom3ditem.h b/src/datavisualization/data/qcustom3ditem.h
index d984b9d4..bec213f9 100644
--- a/src/datavisualization/data/qcustom3ditem.h
+++ b/src/datavisualization/data/qcustom3ditem.h
@@ -45,10 +45,10 @@ class QT_DATAVISUALIZATION_EXPORT QCustom3DItem : public QObject
     Q_PROPERTY(bool scalingAbsolute READ isScalingAbsolute WRITE setScalingAbsolute NOTIFY scalingAbsoluteChanged REVISION 1)
 
 public:
-    explicit QCustom3DItem(QObject *parent = 0);
+    explicit QCustom3DItem(QObject *parent = Q_NULLPTR);
     explicit QCustom3DItem(const QString &meshFile, const QVector3D &position,
                            const QVector3D &scaling, const QQuaternion &rotation,
-                           const QImage &texture, QObject *parent = 0);
+                           const QImage &texture, QObject *parent = Q_NULLPTR);
     virtual ~QCustom3DItem();
 
     void setMeshFile(const QString &meshFile);
@@ -94,7 +94,7 @@ Q_SIGNALS:
     Q_REVISION(1) void scalingAbsoluteChanged(bool scalingAbsolute);
 
 protected:
-    QCustom3DItem(QCustom3DItemPrivate *d, QObject *parent = 0);
+    QCustom3DItem(QCustom3DItemPrivate *d, QObject *parent = Q_NULLPTR);
 
     QScopedPointer<QCustom3DItemPrivate> d_ptr;
 
diff --git a/src/datavisualization/data/qcustom3dlabel.h b/src/datavisualization/data/qcustom3dlabel.h
index 81040a01..798303df 100644
--- a/src/datavisualization/data/qcustom3dlabel.h
+++ b/src/datavisualization/data/qcustom3dlabel.h
@@ -45,10 +45,10 @@ class QT_DATAVISUALIZATION_EXPORT QCustom3DLabel : public QCustom3DItem
     Q_PROPERTY(bool facingCamera READ isFacingCamera WRITE setFacingCamera NOTIFY facingCameraChanged)
 
 public:
-    explicit QCustom3DLabel(QObject *parent = 0);
+    explicit QCustom3DLabel(QObject *parent = Q_NULLPTR);
     explicit QCustom3DLabel(const QString &text, const QFont &font, const QVector3D &position,
                             const QVector3D &scaling, const QQuaternion &rotation,
-                            QObject *parent = 0);
+                            QObject *parent = Q_NULLPTR);
     virtual ~QCustom3DLabel();
 
     void setText(const QString &text);
diff --git a/src/datavisualization/data/qcustom3dvolume.h b/src/datavisualization/data/qcustom3dvolume.h
index 386a8045..966c01f2 100644
--- a/src/datavisualization/data/qcustom3dvolume.h
+++ b/src/datavisualization/data/qcustom3dvolume.h
@@ -54,12 +54,12 @@ class QT_DATAVISUALIZATION_EXPORT QCustom3DVolume : public QCustom3DItem
 
 public:
 
-    explicit QCustom3DVolume(QObject *parent = 0);
+    explicit QCustom3DVolume(QObject *parent = Q_NULLPTR);
     explicit QCustom3DVolume(const QVector3D &position, const QVector3D &scaling,
                              const QQuaternion &rotation, int textureWidth,
                              int textureHeight, int textureDepth,
                              QVector<uchar> *textureData, QImage::Format textureFormat,
-                             const QVector<QRgb> &colorTable, QObject *parent = 0);
+                             const QVector<QRgb> &colorTable, QObject *parent = Q_NULLPTR);
     virtual ~QCustom3DVolume();
 
     void setTextureWidth(int value);
diff --git a/src/datavisualization/data/qheightmapsurfacedataproxy.h b/src/datavisualization/data/qheightmapsurfacedataproxy.h
index d78722af..a6517cd4 100644
--- a/src/datavisualization/data/qheightmapsurfacedataproxy.h
+++ b/src/datavisualization/data/qheightmapsurfacedataproxy.h
@@ -42,9 +42,9 @@ class QT_DATAVISUALIZATION_EXPORT QHeightMapSurfaceDataProxy : public QSurfaceDa
     Q_PROPERTY(float maxZValue READ maxZValue WRITE setMaxZValue NOTIFY maxZValueChanged)
 
 public:
-    explicit QHeightMapSurfaceDataProxy(QObject *parent = 0);
-    explicit QHeightMapSurfaceDataProxy(const QImage &image, QObject *parent = 0);
-    explicit QHeightMapSurfaceDataProxy(const QString &filename, QObject *parent = 0);
+    explicit QHeightMapSurfaceDataProxy(QObject *parent = Q_NULLPTR);
+    explicit QHeightMapSurfaceDataProxy(const QImage &image, QObject *parent = Q_NULLPTR);
+    explicit QHeightMapSurfaceDataProxy(const QString &filename, QObject *parent = Q_NULLPTR);
     virtual ~QHeightMapSurfaceDataProxy();
 
     void setHeightMap(const QImage &image);
@@ -71,7 +71,7 @@ Q_SIGNALS:
     void maxZValueChanged(float value);
 
 protected:
-    explicit QHeightMapSurfaceDataProxy(QHeightMapSurfaceDataProxyPrivate *d, QObject *parent = 0);
+    explicit QHeightMapSurfaceDataProxy(QHeightMapSurfaceDataProxyPrivate *d, QObject *parent = Q_NULLPTR);
     QHeightMapSurfaceDataProxyPrivate *dptr();
     const QHeightMapSurfaceDataProxyPrivate *dptrc() const;
 
diff --git a/src/datavisualization/data/qitemmodelbardataproxy.h b/src/datavisualization/data/qitemmodelbardataproxy.h
index 2e756019..7de8ebf5 100644
--- a/src/datavisualization/data/qitemmodelbardataproxy.h
+++ b/src/datavisualization/data/qitemmodelbardataproxy.h
@@ -62,24 +62,24 @@ public:
         MMBCumulative = 3
     };
 
-    explicit QItemModelBarDataProxy(QObject *parent = 0);
-    QItemModelBarDataProxy(QAbstractItemModel *itemModel, QObject *parent = 0);
-    QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &valueRole,
-                           QObject *parent = 0);
-    QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
-                           const QString &columnRole, const QString &valueRole,
-                           QObject *parent = 0);
-    QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
-                           const QString &columnRole, const QString &valueRole,
-                           const QString &rotationRole, QObject *parent = 0);
-    QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
-                           const QString &columnRole, const QString &valueRole,
-                           const QStringList &rowCategories, const QStringList &columnCategories,
-                           QObject *parent = 0);
-    QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
-                           const QString &columnRole, const QString &valueRole,
-                           const QString &rotationRole, const QStringList &rowCategories,
-                           const QStringList &columnCategories, QObject *parent = 0);
+    explicit QItemModelBarDataProxy(QObject *parent = Q_NULLPTR);
+    explicit QItemModelBarDataProxy(QAbstractItemModel *itemModel, QObject *parent = Q_NULLPTR);
+    explicit QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &valueRole,
+                                    QObject *parent = Q_NULLPTR);
+    explicit QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
+                                    const QString &columnRole, const QString &valueRole,
+                                    QObject *parent = Q_NULLPTR);
+    explicit QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
+                                    const QString &columnRole, const QString &valueRole,
+                                    const QString &rotationRole, QObject *parent = Q_NULLPTR);
+    explicit QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
+                                    const QString &columnRole, const QString &valueRole,
+                                    const QStringList &rowCategories, const QStringList &columnCategories,
+                                    QObject *parent = Q_NULLPTR);
+    explicit QItemModelBarDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
+                                    const QString &columnRole, const QString &valueRole,
+                                    const QString &rotationRole, const QStringList &rowCategories,
+                                    const QStringList &columnCategories, QObject *parent = Q_NULLPTR);
     virtual ~QItemModelBarDataProxy();
 
     void setItemModel(QAbstractItemModel *itemModel);
diff --git a/src/datavisualization/data/qitemmodelscatterdataproxy.h b/src/datavisualization/data/qitemmodelscatterdataproxy.h
index 42666a70..ef186919 100644
--- a/src/datavisualization/data/qitemmodelscatterdataproxy.h
+++ b/src/datavisualization/data/qitemmodelscatterdataproxy.h
@@ -49,15 +49,15 @@ class QT_DATAVISUALIZATION_EXPORT QItemModelScatterDataProxy : public QScatterDa
     Q_PROPERTY(QString rotationRoleReplace READ rotationRoleReplace WRITE setRotationRoleReplace NOTIFY rotationRoleReplaceChanged REVISION 1)
 
 public:
-    explicit QItemModelScatterDataProxy(QObject *parent = 0);
-    QItemModelScatterDataProxy(QAbstractItemModel *itemModel, QObject *parent = 0);
-    QItemModelScatterDataProxy(QAbstractItemModel *itemModel,
-                               const QString &xPosRole, const QString &yPosRole,
-                               const QString &zPosRole, QObject *parent = 0);
-    QItemModelScatterDataProxy(QAbstractItemModel *itemModel,
-                               const QString &xPosRole, const QString &yPosRole,
-                               const QString &zPosRole, const QString &rotationRole,
-                               QObject *parent = 0);
+    explicit QItemModelScatterDataProxy(QObject *parent = Q_NULLPTR);
+    explicit QItemModelScatterDataProxy(QAbstractItemModel *itemModel, QObject *parent = Q_NULLPTR);
+    explicit QItemModelScatterDataProxy(QAbstractItemModel *itemModel,
+                                        const QString &xPosRole, const QString &yPosRole,
+                                        const QString &zPosRole, QObject *parent = Q_NULLPTR);
+    explicit QItemModelScatterDataProxy(QAbstractItemModel *itemModel,
+                                        const QString &xPosRole, const QString &yPosRole,
+                                        const QString &zPosRole, const QString &rotationRole,
+                                        QObject *parent = Q_NULLPTR);
     virtual ~QItemModelScatterDataProxy();
 
     void setItemModel(QAbstractItemModel *itemModel);
diff --git a/src/datavisualization/data/qitemmodelsurfacedataproxy.h b/src/datavisualization/data/qitemmodelsurfacedataproxy.h
index 8ac5f832..a7848e22 100644
--- a/src/datavisualization/data/qitemmodelsurfacedataproxy.h
+++ b/src/datavisualization/data/qitemmodelsurfacedataproxy.h
@@ -66,28 +66,28 @@ public:
         MMBCumulativeY = 3
     };
 
-    explicit QItemModelSurfaceDataProxy(QObject *parent = 0);
-    QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, QObject *parent = 0);
-    QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &yPosRole,
-                               QObject *parent = 0);
-    QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
-                               const QString &columnRole, const QString &yPosRole,
-                               QObject *parent = 0);
-    QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
-                               const QString &columnRole, const QString &xPosRole,
-                               const QString &yPosRole, const QString &zPosRole,
-                               QObject *parent = 0);
-    QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
-                               const QString &columnRole, const QString &yPosRole,
-                               const QStringList &rowCategories,
-                               const QStringList &columnCategories,
-                               QObject *parent = 0);
-    QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
-                               const QString &columnRole, const QString &xPosRole,
-                               const QString &yPosRole, const QString &zPosRole,
-                               const QStringList &rowCategories,
-                               const QStringList &columnCategories,
-                               QObject *parent = 0);
+    explicit QItemModelSurfaceDataProxy(QObject *parent = Q_NULLPTR);
+    explicit QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, QObject *parent = Q_NULLPTR);
+    explicit QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &yPosRole,
+                                        QObject *parent = Q_NULLPTR);
+    explicit QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
+                                        const QString &columnRole, const QString &yPosRole,
+                                        QObject *parent = Q_NULLPTR);
+    explicit QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
+                                        const QString &columnRole, const QString &xPosRole,
+                                        const QString &yPosRole, const QString &zPosRole,
+                                        QObject *parent = Q_NULLPTR);
+    explicit QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
+                                        const QString &columnRole, const QString &yPosRole,
+                                        const QStringList &rowCategories,
+                                        const QStringList &columnCategories,
+                                        QObject *parent = Q_NULLPTR);
+    explicit QItemModelSurfaceDataProxy(QAbstractItemModel *itemModel, const QString &rowRole,
+                                        const QString &columnRole, const QString &xPosRole,
+                                        const QString &yPosRole, const QString &zPosRole,
+                                        const QStringList &rowCategories,
+                                        const QStringList &columnCategories,
+                                        QObject *parent = Q_NULLPTR);
     virtual ~QItemModelSurfaceDataProxy();
 
     void setItemModel(QAbstractItemModel *itemModel);
diff --git a/src/datavisualization/data/qscatter3dseries.h b/src/datavisualization/data/qscatter3dseries.h
index 8a0bce5b..b88dcda2 100644
--- a/src/datavisualization/data/qscatter3dseries.h
+++ b/src/datavisualization/data/qscatter3dseries.h
@@ -37,8 +37,8 @@ class QT_DATAVISUALIZATION_EXPORT QScatter3DSeries : public QAbstract3DSeries
     Q_PROPERTY(float itemSize READ itemSize WRITE setItemSize NOTIFY itemSizeChanged)
 
 public:
-    explicit QScatter3DSeries(QObject *parent = 0);
-    explicit QScatter3DSeries(QScatterDataProxy *dataProxy, QObject *parent = 0);
+    explicit QScatter3DSeries(QObject *parent = Q_NULLPTR);
+    explicit QScatter3DSeries(QScatterDataProxy *dataProxy, QObject *parent = Q_NULLPTR);
     virtual ~QScatter3DSeries();
 
     void setDataProxy(QScatterDataProxy *proxy);
@@ -57,7 +57,7 @@ Q_SIGNALS:
     void itemSizeChanged(float size);
 
 protected:
-    explicit QScatter3DSeries(QScatter3DSeriesPrivate *d, QObject *parent = 0);
+    explicit QScatter3DSeries(QScatter3DSeriesPrivate *d, QObject *parent = Q_NULLPTR);
     QScatter3DSeriesPrivate *dptr();
     const QScatter3DSeriesPrivate *dptrc() const;
 
diff --git a/src/datavisualization/data/qscatterdataproxy.h b/src/datavisualization/data/qscatterdataproxy.h
index 19c4c86a..92354354 100644
--- a/src/datavisualization/data/qscatterdataproxy.h
+++ b/src/datavisualization/data/qscatterdataproxy.h
@@ -43,7 +43,7 @@ class QT_DATAVISUALIZATION_EXPORT QScatterDataProxy : public QAbstractDataProxy
     Q_PROPERTY(QScatter3DSeries *series READ series NOTIFY seriesChanged)
 
 public:
-    explicit QScatterDataProxy(QObject *parent = 0);
+    explicit QScatterDataProxy(QObject *parent = Q_NULLPTR);
     virtual ~QScatterDataProxy();
 
     QScatter3DSeries *series() const;
@@ -75,7 +75,7 @@ Q_SIGNALS:
     void seriesChanged(QScatter3DSeries *series);
 
 protected:
-    explicit QScatterDataProxy(QScatterDataProxyPrivate *d, QObject *parent = 0);
+    explicit QScatterDataProxy(QScatterDataProxyPrivate *d, QObject *parent = Q_NULLPTR);
     QScatterDataProxyPrivate *dptr();
     const QScatterDataProxyPrivate *dptrc() const;
 
diff --git a/src/datavisualization/data/qsurface3dseries.h b/src/datavisualization/data/qsurface3dseries.h
index ffdbcb62..b99213ce 100644
--- a/src/datavisualization/data/qsurface3dseries.h
+++ b/src/datavisualization/data/qsurface3dseries.h
@@ -49,8 +49,8 @@ public:
     };
     Q_DECLARE_FLAGS(DrawFlags, DrawFlag)
 
-    explicit QSurface3DSeries(QObject *parent = 0);
-    explicit QSurface3DSeries(QSurfaceDataProxy *dataProxy, QObject *parent = 0);
+    explicit QSurface3DSeries(QObject *parent = Q_NULLPTR);
+    explicit QSurface3DSeries(QSurfaceDataProxy *dataProxy, QObject *parent = Q_NULLPTR);
     virtual ~QSurface3DSeries();
 
     void setDataProxy(QSurfaceDataProxy *proxy);
@@ -83,7 +83,7 @@ Q_SIGNALS:
     void textureFileChanged(const QString &filename);
 
 protected:
-    explicit QSurface3DSeries(QSurface3DSeriesPrivate *d, QObject *parent = 0);
+    explicit QSurface3DSeries(QSurface3DSeriesPrivate *d, QObject *parent = Q_NULLPTR);
     QSurface3DSeriesPrivate *dptr();
     const QSurface3DSeriesPrivate *dptrc() const;
 
diff --git a/src/datavisualization/data/qsurfacedataproxy.h b/src/datavisualization/data/qsurfacedataproxy.h
index 609a6273..3c4ba7ac 100644
--- a/src/datavisualization/data/qsurfacedataproxy.h
+++ b/src/datavisualization/data/qsurfacedataproxy.h
@@ -45,7 +45,7 @@ class QT_DATAVISUALIZATION_EXPORT QSurfaceDataProxy : public QAbstractDataProxy
     Q_PROPERTY(QSurface3DSeries *series READ series NOTIFY seriesChanged)
 
 public:
-    explicit QSurfaceDataProxy(QObject *parent = 0);
+    explicit QSurfaceDataProxy(QObject *parent = Q_NULLPTR);
     virtual ~QSurfaceDataProxy();
 
     QSurface3DSeries *series() const;
@@ -84,7 +84,7 @@ Q_SIGNALS:
     void seriesChanged(QSurface3DSeries *series);
 
 protected:
-    explicit QSurfaceDataProxy(QSurfaceDataProxyPrivate *d, QObject *parent = 0);
+    explicit QSurfaceDataProxy(QSurfaceDataProxyPrivate *d, QObject *parent = Q_NULLPTR);
     QSurfaceDataProxyPrivate *dptr();
     const QSurfaceDataProxyPrivate *dptrc() const;
 
diff --git a/src/datavisualization/engine/q3dbars.h b/src/datavisualization/engine/q3dbars.h
index e910571e..55fec1d2 100644
--- a/src/datavisualization/engine/q3dbars.h
+++ b/src/datavisualization/engine/q3dbars.h
@@ -46,7 +46,7 @@ class QT_DATAVISUALIZATION_EXPORT Q3DBars : public QAbstract3DGraph
     Q_PROPERTY(float floorLevel READ floorLevel WRITE setFloorLevel NOTIFY floorLevelChanged)
 
 public:
-    explicit Q3DBars(const QSurfaceFormat *format = 0, QWindow *parent = 0);
+    explicit Q3DBars(const QSurfaceFormat *format = Q_NULLPTR, QWindow *parent = Q_NULLPTR);
     virtual ~Q3DBars();
 
     void setPrimarySeries(QBar3DSeries *series);
diff --git a/src/datavisualization/engine/q3dcamera.h b/src/datavisualization/engine/q3dcamera.h
index 60e1f303..5fd2d25d 100644
--- a/src/datavisualization/engine/q3dcamera.h
+++ b/src/datavisualization/engine/q3dcamera.h
@@ -71,7 +71,7 @@ public:
         CameraPresetDirectlyBelow
     };
 
-    Q3DCamera(QObject *parent = 0);
+    explicit Q3DCamera(QObject *parent = Q_NULLPTR);
     virtual ~Q3DCamera();
 
     float xRotation() const;
diff --git a/src/datavisualization/engine/q3dlight.h b/src/datavisualization/engine/q3dlight.h
index 760766c0..aaedd552 100644
--- a/src/datavisualization/engine/q3dlight.h
+++ b/src/datavisualization/engine/q3dlight.h
@@ -33,7 +33,7 @@ class QT_DATAVISUALIZATION_EXPORT Q3DLight : public Q3DObject
     Q_OBJECT
 
 public:
-    Q3DLight(QObject *parent = 0);
+    explicit Q3DLight(QObject *parent = Q_NULLPTR);
     virtual ~Q3DLight();
 
 private:
diff --git a/src/datavisualization/engine/q3dobject.h b/src/datavisualization/engine/q3dobject.h
index 636cd295..bbafa60c 100644
--- a/src/datavisualization/engine/q3dobject.h
+++ b/src/datavisualization/engine/q3dobject.h
@@ -38,7 +38,7 @@ class QT_DATAVISUALIZATION_EXPORT Q3DObject : public QObject
     Q_PROPERTY(QVector3D position READ position WRITE setPosition NOTIFY positionChanged)
 
 public:
-    Q3DObject(QObject *parent = 0);
+    explicit Q3DObject(QObject *parent = Q_NULLPTR);
     virtual ~Q3DObject();
 
     virtual void copyValuesFrom(const Q3DObject &source);
diff --git a/src/datavisualization/engine/q3dscatter.h b/src/datavisualization/engine/q3dscatter.h
index 4b1c805c..af98c03f 100644
--- a/src/datavisualization/engine/q3dscatter.h
+++ b/src/datavisualization/engine/q3dscatter.h
@@ -39,7 +39,7 @@ class QT_DATAVISUALIZATION_EXPORT Q3DScatter : public QAbstract3DGraph
     Q_PROPERTY(QScatter3DSeries *selectedSeries READ selectedSeries NOTIFY selectedSeriesChanged)
 
 public:
-    explicit Q3DScatter(const QSurfaceFormat *format = 0, QWindow *parent = 0);
+    explicit Q3DScatter(const QSurfaceFormat *format = Q_NULLPTR, QWindow *parent = Q_NULLPTR);
     virtual ~Q3DScatter();
 
     void addSeries(QScatter3DSeries *series);
diff --git a/src/datavisualization/engine/q3dscene.h b/src/datavisualization/engine/q3dscene.h
index 4dd39954..53126d05 100644
--- a/src/datavisualization/engine/q3dscene.h
+++ b/src/datavisualization/engine/q3dscene.h
@@ -47,7 +47,7 @@ class QT_DATAVISUALIZATION_EXPORT Q3DScene : public QObject
     Q_PROPERTY(QPoint graphPositionQuery READ graphPositionQuery WRITE setGraphPositionQuery NOTIFY graphPositionQueryChanged REVISION 1)
 
 public:
-    Q3DScene(QObject *parent = 0);
+    explicit Q3DScene(QObject *parent = Q_NULLPTR);
     virtual ~Q3DScene();
 
     QRect viewport() const;
diff --git a/src/datavisualization/engine/q3dsurface.h b/src/datavisualization/engine/q3dsurface.h
index 28111d5c..939b634b 100644
--- a/src/datavisualization/engine/q3dsurface.h
+++ b/src/datavisualization/engine/q3dsurface.h
@@ -40,7 +40,7 @@ class QT_DATAVISUALIZATION_EXPORT Q3DSurface : public QAbstract3DGraph
     Q_PROPERTY(bool flipHorizontalGrid READ flipHorizontalGrid WRITE setFlipHorizontalGrid NOTIFY flipHorizontalGridChanged)
 
 public:
-    explicit Q3DSurface(const QSurfaceFormat *format = 0, QWindow *parent = 0);
+    explicit Q3DSurface(const QSurfaceFormat *format = Q_NULLPTR, QWindow *parent = Q_NULLPTR);
     virtual ~Q3DSurface();
 
     void addSeries(QSurface3DSeries *series);
diff --git a/src/datavisualization/engine/qabstract3dgraph.h b/src/datavisualization/engine/qabstract3dgraph.h
index 13e2faf0..45057e71 100644
--- a/src/datavisualization/engine/qabstract3dgraph.h
+++ b/src/datavisualization/engine/qabstract3dgraph.h
@@ -65,7 +65,7 @@ class QT_DATAVISUALIZATION_EXPORT QAbstract3DGraph : public QWindow, protected Q
 
 protected:
     explicit QAbstract3DGraph(QAbstract3DGraphPrivate *d, const QSurfaceFormat *format,
-                              QWindow *parent = 0);
+                              QWindow *parent = Q_NULLPTR);
 
 public:
     enum SelectionFlag {
diff --git a/src/datavisualization/input/q3dinputhandler.h b/src/datavisualization/input/q3dinputhandler.h
index 94357f2c..74847637 100644
--- a/src/datavisualization/input/q3dinputhandler.h
+++ b/src/datavisualization/input/q3dinputhandler.h
@@ -37,7 +37,7 @@ class QT_DATAVISUALIZATION_EXPORT Q3DInputHandler : public QAbstract3DInputHandl
     Q_PROPERTY(bool zoomAtTargetEnabled READ isZoomAtTargetEnabled WRITE setZoomAtTargetEnabled NOTIFY zoomAtTargetEnabledChanged)
 
 public:
-    explicit Q3DInputHandler(QObject *parent = 0);
+    explicit Q3DInputHandler(QObject *parent = Q_NULLPTR);
     virtual ~Q3DInputHandler();
 
     void setRotationEnabled(bool enable);
diff --git a/src/datavisualization/input/qabstract3dinputhandler.h b/src/datavisualization/input/qabstract3dinputhandler.h
index 64623e67..317cba1f 100644
--- a/src/datavisualization/input/qabstract3dinputhandler.h
+++ b/src/datavisualization/input/qabstract3dinputhandler.h
@@ -50,7 +50,7 @@ public:
     };
 
 protected:
-    explicit QAbstract3DInputHandler(QObject *parent = 0);
+    explicit QAbstract3DInputHandler(QObject *parent = Q_NULLPTR);
 public:
     virtual ~QAbstract3DInputHandler();
 
diff --git a/src/datavisualization/input/qtouch3dinputhandler.h b/src/datavisualization/input/qtouch3dinputhandler.h
index 9228b89e..d1ab3c29 100644
--- a/src/datavisualization/input/qtouch3dinputhandler.h
+++ b/src/datavisualization/input/qtouch3dinputhandler.h
@@ -33,7 +33,7 @@ class QT_DATAVISUALIZATION_EXPORT QTouch3DInputHandler : public Q3DInputHandler
     Q_OBJECT
 
 public:
-    explicit QTouch3DInputHandler(QObject *parent = 0);
+    explicit QTouch3DInputHandler(QObject *parent = Q_NULLPTR);
     virtual ~QTouch3DInputHandler();
 
     // Input event listeners
diff --git a/src/datavisualization/theme/q3dtheme.h b/src/datavisualization/theme/q3dtheme.h
index 63ed0c47..236320bf 100644
--- a/src/datavisualization/theme/q3dtheme.h
+++ b/src/datavisualization/theme/q3dtheme.h
@@ -80,8 +80,8 @@ public:
     };
 
 public:
-    explicit Q3DTheme(QObject *parent = 0);
-    explicit Q3DTheme(Theme themeType, QObject *parent = 0);
+    explicit Q3DTheme(QObject *parent = Q_NULLPTR);
+    explicit Q3DTheme(Theme themeType, QObject *parent = Q_NULLPTR);
     virtual ~Q3DTheme();
 
     void setType(Theme themeType);
@@ -175,7 +175,7 @@ Q_SIGNALS:
     void colorStyleChanged(Q3DTheme::ColorStyle style);
 
 protected:
-    explicit Q3DTheme(Q3DThemePrivate *d, Theme themeType, QObject *parent = 0);
+    explicit Q3DTheme(Q3DThemePrivate *d, Theme themeType, QObject *parent = Q_NULLPTR);
 
     QScopedPointer<Q3DThemePrivate> d_ptr;
 
diff --git a/src/datavisualization/utils/qutils.h b/src/datavisualization/utils/qutils.h
index 078a78df..9920a00c 100644
--- a/src/datavisualization/utils/qutils.h
+++ b/src/datavisualization/utils/qutils.h
@@ -44,7 +44,7 @@ static inline QSurfaceFormat qDefaultSurfaceFormat(bool antialias)
     surfaceFormat.setRenderableType(QSurfaceFormat::DefaultRenderableType);
 
     QOpenGLContext *ctx = QOpenGLContext::currentContext();
-    QOffscreenSurface *dummySurface = 0;
+    QOffscreenSurface *dummySurface = Q_NULLPTR;
     if (!ctx) {
         dummySurface = new QOffscreenSurface();
         dummySurface->setFormat(surfaceFormat);