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.

Task-number: QTBUG-45291
Change-Id: Ied526fb2d7adc3a68946d6843a6bd6f475ebf864
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

23 files changed, 106 insertions, 75 deletions

diff --git a/src/qml/jsapi/qjsengine.h b/src/qml/jsapi/qjsengine.h
index 40b0a60369..c3f3ace1dd 100644
--- a/src/qml/jsapi/qjsengine.h
+++ b/src/qml/jsapi/qjsengine.h
@@ -105,7 +105,7 @@ private:
     friend inline bool qjsvalue_cast_helper(const QJSValue &, int, void *);
 
 protected:
-    QJSEngine(QJSEnginePrivate &dd, QObject *parent = 0);
+    QJSEngine(QJSEnginePrivate &dd, QObject *parent = Q_NULLPTR);
 
 private:
     QV8Engine *d;
diff --git a/src/qml/qml/qqml.h b/src/qml/qml/qqml.h
index 23cb69e2f1..02618f77f5 100644
--- a/src/qml/qml/qqml.h
+++ b/src/qml/qml/qqml.h
@@ -105,10 +105,11 @@ int qmlRegisterType()
 
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
-        0, 0,
+        0,
+        Q_NULLPTR,
         QString(),
 
-        0, 0, 0, 0, &T::staticMetaObject,
+        Q_NULLPTR, 0, 0, Q_NULLPTR, &T::staticMetaObject,
 
         QQmlPrivate::attachedPropertiesFunc<T>(),
         QQmlPrivate::attachedPropertiesMetaObject<T>(),
@@ -117,9 +118,9 @@ int qmlRegisterType()
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        0, 0,
+        Q_NULLPTR, Q_NULLPTR,
 
-        0,
+        Q_NULLPTR,
         0
     };
 
@@ -138,7 +139,8 @@ int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMin
 
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
-        0, 0,
+        0,
+        Q_NULLPTR,
         reason,
 
         uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
@@ -150,9 +152,9 @@ int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMin
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        0, 0,
+        Q_NULLPTR, Q_NULLPTR,
 
-        0,
+        Q_NULLPTR,
         0
     };
 
@@ -169,7 +171,8 @@ int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMin
 
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
-        0, 0,
+        0,
+        Q_NULLPTR,
         reason,
 
         uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
@@ -181,9 +184,9 @@ int qmlRegisterUncreatableType(const char *uri, int versionMajor, int versionMin
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        0, 0,
+        Q_NULLPTR, Q_NULLPTR,
 
-        0,
+        Q_NULLPTR,
         metaObjectRevision
     };
 
@@ -207,7 +210,8 @@ int qmlRegisterExtendedUncreatableType(const char *uri, int versionMajor, int ve
 
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
-        0, 0,
+        0,
+        Q_NULLPTR,
         reason,
 
         uri, versionMajor, versionMinor, qmlName, &T::staticMetaObject,
@@ -221,7 +225,7 @@ int qmlRegisterExtendedUncreatableType(const char *uri, int versionMajor, int ve
 
         QQmlPrivate::createParent<E>, &E::staticMetaObject,
 
-        0,
+        Q_NULLPTR,
         0
     };
 
@@ -250,9 +254,9 @@ int qmlRegisterType(const char *uri, int versionMajor, int versionMinor, const c
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        0, 0,
+        Q_NULLPTR, Q_NULLPTR,
 
-        0,
+        Q_NULLPTR,
         0
     };
 
@@ -281,9 +285,9 @@ int qmlRegisterType(const char *uri, int versionMajor, int versionMinor, const c
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        0, 0,
+        Q_NULLPTR, Q_NULLPTR,
 
-        0,
+        Q_NULLPTR,
         metaObjectRevision
     };
 
@@ -312,9 +316,9 @@ int qmlRegisterRevision(const char *uri, int versionMajor, int versionMinor)
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        0, 0,
+        Q_NULLPTR, Q_NULLPTR,
 
-        0,
+        Q_NULLPTR,
         metaObjectRevision
     };
 
@@ -332,10 +336,11 @@ int qmlRegisterExtendedType()
 
         qRegisterNormalizedMetaType<T *>(pointerName.constData()),
         qRegisterNormalizedMetaType<QQmlListProperty<T> >(listName.constData()),
-        0, 0,
+        0,
+        Q_NULLPTR,
         QString(),
 
-        0, 0, 0, 0, &T::staticMetaObject,
+        Q_NULLPTR, 0, 0, Q_NULLPTR, &T::staticMetaObject,
 
         QQmlPrivate::attachedPropertiesFunc<T>(),
         QQmlPrivate::attachedPropertiesMetaObject<T>(),
@@ -346,7 +351,7 @@ int qmlRegisterExtendedType()
 
         QQmlPrivate::createParent<E>, &E::staticMetaObject,
 
-        0,
+        Q_NULLPTR,
         0
     };
 
@@ -385,7 +390,7 @@ int qmlRegisterExtendedType(const char *uri, int versionMajor, int versionMinor,
 
         QQmlPrivate::createParent<E>, &E::staticMetaObject,
 
-        0,
+        Q_NULLPTR,
         0
     };
 
@@ -435,7 +440,7 @@ int qmlRegisterCustomType(const char *uri, int versionMajor, int versionMinor,
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueSource>::cast(),
         QQmlPrivate::StaticCastSelector<T,QQmlPropertyValueInterceptor>::cast(),
 
-        0, 0,
+        Q_NULLPTR, Q_NULLPTR,
 
         parser,
         0
@@ -530,7 +535,7 @@ inline int qmlRegisterSingletonType(const char *uri, int versionMajor, int versi
 
         uri, versionMajor, versionMinor, typeName,
 
-        callback, 0, 0, 0, 0
+        callback, Q_NULLPTR, Q_NULLPTR, 0, 0
     };
 
     return QQmlPrivate::qmlregister(QQmlPrivate::SingletonRegistration, &api);
@@ -548,7 +553,7 @@ inline int qmlRegisterSingletonType(const char *uri, int versionMajor, int versi
 
         uri, versionMajor, versionMinor, typeName,
 
-        0, callback, &T::staticMetaObject, qRegisterNormalizedMetaType<T *>(pointerName.constData()), 0
+        Q_NULLPTR, callback, &T::staticMetaObject, qRegisterNormalizedMetaType<T *>(pointerName.constData()), 0
     };
 
     return QQmlPrivate::qmlregister(QQmlPrivate::SingletonRegistration, &api);
diff --git a/src/qml/qml/qqmlapplicationengine.h b/src/qml/qml/qqmlapplicationengine.h
index 84cb2625dc..3b91d6adfc 100644
--- a/src/qml/qml/qqmlapplicationengine.h
+++ b/src/qml/qml/qqmlapplicationengine.h
@@ -47,9 +47,9 @@ class Q_QML_EXPORT QQmlApplicationEngine : public QQmlEngine
 {
     Q_OBJECT
 public:
-    QQmlApplicationEngine(QObject *parent=0);
-    QQmlApplicationEngine(const QUrl &url, QObject *parent=0);
-    QQmlApplicationEngine(const QString &filePath, QObject *parent=0);
+    QQmlApplicationEngine(QObject *parent = Q_NULLPTR);
+    QQmlApplicationEngine(const QUrl &url, QObject *parent = Q_NULLPTR);
+    QQmlApplicationEngine(const QString &filePath, QObject *parent = Q_NULLPTR);
     ~QQmlApplicationEngine();
 
     QList<QObject*> rootObjects();
diff --git a/src/qml/qml/qqmlcomponent.h b/src/qml/qml/qqmlcomponent.h
index 121c83db5c..58cbadff00 100644
--- a/src/qml/qml/qqmlcomponent.h
+++ b/src/qml/qml/qqmlcomponent.h
@@ -66,12 +66,12 @@ public:
     enum CompilationMode { PreferSynchronous, Asynchronous };
     Q_ENUM(CompilationMode)
 
-    QQmlComponent(QObject *parent = 0);
-    QQmlComponent(QQmlEngine *, QObject *parent=0);
-    QQmlComponent(QQmlEngine *, const QString &fileName, QObject *parent = 0);
-    QQmlComponent(QQmlEngine *, const QString &fileName, CompilationMode mode, QObject *parent = 0);
-    QQmlComponent(QQmlEngine *, const QUrl &url, QObject *parent = 0);
-    QQmlComponent(QQmlEngine *, const QUrl &url, CompilationMode mode, QObject *parent = 0);
+    QQmlComponent(QObject *parent = Q_NULLPTR);
+    QQmlComponent(QQmlEngine *, QObject *parent = Q_NULLPTR);
+    QQmlComponent(QQmlEngine *, const QString &fileName, QObject *parent = Q_NULLPTR);
+    QQmlComponent(QQmlEngine *, const QString &fileName, CompilationMode mode, QObject *parent = Q_NULLPTR);
+    QQmlComponent(QQmlEngine *, const QUrl &url, QObject *parent = Q_NULLPTR);
+    QQmlComponent(QQmlEngine *, const QUrl &url, CompilationMode mode, QObject *parent = Q_NULLPTR);
     virtual ~QQmlComponent();
 
     enum Status { Null, Ready, Loading, Error };
@@ -90,12 +90,12 @@ public:
 
     QUrl url() const;
 
-    virtual QObject *create(QQmlContext *context = 0);
+    virtual QObject *create(QQmlContext *context = Q_NULLPTR);
     virtual QObject *beginCreate(QQmlContext *);
     virtual void completeCreate();
 
-    void create(QQmlIncubator &, QQmlContext *context = 0,
-                QQmlContext *forContext = 0);
+    void create(QQmlIncubator &, QQmlContext *context = Q_NULLPTR,
+                QQmlContext *forContext = Q_NULLPTR);
 
     QQmlContext *creationContext() const;
 
diff --git a/src/qml/qml/qqmlcontext.h b/src/qml/qml/qqmlcontext.h
index e69a2f8f69..3049ec7f71 100644
--- a/src/qml/qml/qqmlcontext.h
+++ b/src/qml/qml/qqmlcontext.h
@@ -56,8 +56,8 @@ class Q_QML_EXPORT QQmlContext : public QObject
     Q_DECLARE_PRIVATE(QQmlContext)
 
 public:
-    QQmlContext(QQmlEngine *parent, QObject *objParent=0);
-    QQmlContext(QQmlContext *parent, QObject *objParent=0);
+    QQmlContext(QQmlEngine *parent, QObject *objParent = Q_NULLPTR);
+    QQmlContext(QQmlContext *parent, QObject *objParent = Q_NULLPTR);
     virtual ~QQmlContext();
 
     bool isValid() const;
diff --git a/src/qml/qml/qqmlengine.h b/src/qml/qml/qqmlengine.h
index 61a884279d..a0d47c33a6 100644
--- a/src/qml/qml/qqmlengine.h
+++ b/src/qml/qml/qqmlengine.h
@@ -88,7 +88,7 @@ class Q_QML_EXPORT QQmlEngine : public QJSEngine
     Q_PROPERTY(QString offlineStoragePath READ offlineStoragePath WRITE setOfflineStoragePath)
     Q_OBJECT
 public:
-    QQmlEngine(QObject *p = 0);
+    QQmlEngine(QObject *p = Q_NULLPTR);
     virtual ~QQmlEngine();
 
     QQmlContext *rootContext() const;
diff --git a/src/qml/qml/qqmlexpression.h b/src/qml/qml/qqmlexpression.h
index 408871cfc5..e3e96f8030 100644
--- a/src/qml/qml/qqmlexpression.h
+++ b/src/qml/qml/qqmlexpression.h
@@ -54,8 +54,8 @@ class Q_QML_EXPORT QQmlExpression : public QObject
     Q_OBJECT
 public:
     QQmlExpression();
-    QQmlExpression(QQmlContext *, QObject *, const QString &, QObject * = 0);
-    explicit QQmlExpression(const QQmlScriptString &, QQmlContext * = 0, QObject * = 0, QObject * = 0);
+    QQmlExpression(QQmlContext *, QObject *, const QString &, QObject * = Q_NULLPTR);
+    explicit QQmlExpression(const QQmlScriptString &, QQmlContext * = Q_NULLPTR, QObject * = Q_NULLPTR, QObject * = Q_NULLPTR);
     virtual ~QQmlExpression();
 
     QQmlEngine *engine() const;
@@ -78,7 +78,7 @@ public:
     void clearError();
     QQmlError error() const;
 
-    QVariant evaluate(bool *valueIsUndefined = 0);
+    QVariant evaluate(bool *valueIsUndefined = Q_NULLPTR);
 
 Q_SIGNALS:
     void valueChanged();
diff --git a/src/qml/qml/qqmlextensionplugin.h b/src/qml/qml/qqmlextensionplugin.h
index 879cc91abe..074b5e2531 100644
--- a/src/qml/qml/qqmlextensionplugin.h
+++ b/src/qml/qml/qqmlextensionplugin.h
@@ -52,7 +52,7 @@ class Q_QML_EXPORT QQmlExtensionPlugin
     Q_INTERFACES(QQmlExtensionInterface)
     Q_INTERFACES(QQmlTypesExtensionInterface)
 public:
-    explicit QQmlExtensionPlugin(QObject *parent = 0);
+    explicit QQmlExtensionPlugin(QObject *parent = Q_NULLPTR);
     ~QQmlExtensionPlugin();
 
     QUrl baseUrl() const;
diff --git a/src/qml/qml/qqmlfileselector.h b/src/qml/qml/qqmlfileselector.h
index d86908e9cb..3af63a8293 100644
--- a/src/qml/qml/qqmlfileselector.h
+++ b/src/qml/qml/qqmlfileselector.h
@@ -48,7 +48,7 @@ class Q_QML_EXPORT QQmlFileSelector : public QObject
     Q_OBJECT
     Q_DECLARE_PRIVATE(QQmlFileSelector)
 public:
-    QQmlFileSelector(QQmlEngine* engine, QObject* parent=0);
+    QQmlFileSelector(QQmlEngine *engine, QObject *parent = Q_NULLPTR);
     ~QQmlFileSelector();
     void setSelector(QFileSelector *selector);
     void setExtraSelectors(QStringList &strings); // TODO Qt6: remove
diff --git a/src/qml/qml/qqmllist.h b/src/qml/qml/qqmllist.h
index edd61b26c9..5a06299f3b 100644
--- a/src/qml/qml/qqmllist.h
+++ b/src/qml/qml/qqmllist.h
@@ -55,15 +55,41 @@ public:
     typedef void (*ClearFunction)(QQmlListProperty<T> *);
 
     QQmlListProperty()
-        : object(0), data(0), append(0), count(0), at(0), clear(0), dummy1(0), dummy2(0) {}
+        : object(Q_NULLPTR),
+          data(Q_NULLPTR),
+          append(Q_NULLPTR),
+          count(Q_NULLPTR),
+          at(Q_NULLPTR),
+          clear(Q_NULLPTR),
+          dummy1(Q_NULLPTR),
+          dummy2(Q_NULLPTR)
+    {}
     QQmlListProperty(QObject *o, QList<T *> &list)
         : object(o), data(&list), append(qlist_append), count(qlist_count), at(qlist_at),
-          clear(qlist_clear), dummy1(0), dummy2(0) {}
+          clear(qlist_clear),
+          dummy1(Q_NULLPTR),
+          dummy2(Q_NULLPTR)
+    {}
     QQmlListProperty(QObject *o, void *d, AppendFunction a, CountFunction c, AtFunction t,
                     ClearFunction r )
-        : object(o), data(d), append(a), count(c), at(t), clear(r), dummy1(0), dummy2(0) {}
+        : object(o),
+          data(d),
+          append(a),
+          count(c),
+          at(t),
+          clear(r),
+          dummy1(Q_NULLPTR),
+          dummy2(Q_NULLPTR)
+    {}
     QQmlListProperty(QObject *o, void *d, CountFunction c, AtFunction t)
-        : object(o), data(d), append(0), count(c), at(t), clear(0), dummy1(0), dummy2(0) {}
+        : object(o),
+          data(d),
+          append(Q_NULLPTR),
+          count(c), at(t),
+          clear(Q_NULLPTR),
+          dummy1(Q_NULLPTR),
+          dummy2(Q_NULLPTR)
+    {}
     bool operator==(const QQmlListProperty &o) const {
         return object == o.object &&
                data == o.data &&
@@ -108,7 +134,7 @@ class Q_QML_EXPORT QQmlListReference
 {
 public:
     QQmlListReference();
-    QQmlListReference(QObject *, const char *property, QQmlEngine * = 0);
+    QQmlListReference(QObject *, const char *property, QQmlEngine * = Q_NULLPTR);
     QQmlListReference(const QQmlListReference &);
     QQmlListReference &operator=(const QQmlListReference &);
     ~QQmlListReference();
diff --git a/src/qml/util/qqmlpropertymap.h b/src/qml/util/qqmlpropertymap.h
index 685f771452..028a299eec 100644
--- a/src/qml/util/qqmlpropertymap.h
+++ b/src/qml/util/qqmlpropertymap.h
@@ -49,7 +49,7 @@ class Q_QML_EXPORT QQmlPropertyMap : public QObject
 {
     Q_OBJECT
 public:
-    explicit QQmlPropertyMap(QObject *parent = 0);
+    explicit QQmlPropertyMap(QObject *parent = Q_NULLPTR);
     virtual ~QQmlPropertyMap();
 
     QVariant value(const QString &key) const;
diff --git a/src/quick/items/qquickframebufferobject.h b/src/quick/items/qquickframebufferobject.h
index 7fb7262222..ec40e7e97e 100644
--- a/src/quick/items/qquickframebufferobject.h
+++ b/src/quick/items/qquickframebufferobject.h
@@ -69,7 +69,7 @@ public:
         void *data;
     };
 
-    QQuickFramebufferObject(QQuickItem *parent = 0);
+    QQuickFramebufferObject(QQuickItem *parent = Q_NULLPTR);
 
     bool textureFollowsItemSize() const;
     void setTextureFollowsItemSize(bool follows);
diff --git a/src/quick/items/qquickitem.h b/src/quick/items/qquickitem.h
index bda6dd4da5..bf208e1f3e 100644
--- a/src/quick/items/qquickitem.h
+++ b/src/quick/items/qquickitem.h
@@ -53,7 +53,7 @@ class Q_QUICK_EXPORT QQuickTransform : public QObject
 {
     Q_OBJECT
 public:
-    QQuickTransform(QObject *parent = 0);
+    explicit QQuickTransform(QObject *parent = Q_NULLPTR);
     ~QQuickTransform();
 
     void appendToItem(QQuickItem *);
@@ -189,7 +189,7 @@ public:
     };
     Q_ENUM(TransformOrigin)
 
-    QQuickItem(QQuickItem *parent = 0);
+    explicit QQuickItem(QQuickItem *parent = Q_NULLPTR);
     virtual ~QQuickItem();
 
     QQuickWindow *window() const;
@@ -430,7 +430,7 @@ protected:
     virtual void updatePolish();
 
 protected:
-    QQuickItem(QQuickItemPrivate &dd, QQuickItem *parent = 0);
+    QQuickItem(QQuickItemPrivate &dd, QQuickItem *parent = Q_NULLPTR);
 
 private:
     Q_PRIVATE_SLOT(d_func(), void _q_resourceObjectDeleted(QObject *))
diff --git a/src/quick/items/qquickitemgrabresult.h b/src/quick/items/qquickitemgrabresult.h
index 055cd09095..027ed19d9e 100644
--- a/src/quick/items/qquickitemgrabresult.h
+++ b/src/quick/items/qquickitemgrabresult.h
@@ -73,7 +73,7 @@ private Q_SLOTS:
 private:
     friend class QQuickItem;
 
-    QQuickItemGrabResult(QObject *parent = 0);
+    QQuickItemGrabResult(QObject *parent = Q_NULLPTR);
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/items/qquickpainteditem.h b/src/quick/items/qquickpainteditem.h
index 8c9ae2eebb..85e90e7263 100644
--- a/src/quick/items/qquickpainteditem.h
+++ b/src/quick/items/qquickpainteditem.h
@@ -51,7 +51,7 @@ class Q_QUICK_EXPORT QQuickPaintedItem : public QQuickItem
     Q_PROPERTY(QSize textureSize READ textureSize WRITE setTextureSize NOTIFY textureSizeChanged)
 
 public:
-    QQuickPaintedItem(QQuickItem *parent = 0);
+    QQuickPaintedItem(QQuickItem *parent = Q_NULLPTR);
     virtual ~QQuickPaintedItem();
 
     enum RenderTarget {
@@ -112,7 +112,7 @@ Q_SIGNALS:
     void textureSizeChanged();
 
 protected:
-    QQuickPaintedItem(QQuickPaintedItemPrivate &dd, QQuickItem *parent = 0);
+    QQuickPaintedItem(QQuickPaintedItemPrivate &dd, QQuickItem *parent = Q_NULLPTR);
     QSGNode *updatePaintNode(QSGNode *, UpdatePaintNodeData *) Q_DECL_OVERRIDE;
     void releaseResources() Q_DECL_OVERRIDE;
 
diff --git a/src/quick/items/qquickrendercontrol.h b/src/quick/items/qquickrendercontrol.h
index ff80acf766..1132585a66 100644
--- a/src/quick/items/qquickrendercontrol.h
+++ b/src/quick/items/qquickrendercontrol.h
@@ -49,7 +49,7 @@ class Q_QUICK_EXPORT QQuickRenderControl : public QObject
     Q_OBJECT
 
 public:
-    QQuickRenderControl(QObject *parent = 0);
+    QQuickRenderControl(QObject *parent = Q_NULLPTR);
     ~QQuickRenderControl();
 
     void prepareThread(QThread *targetThread);
@@ -62,8 +62,8 @@ public:
 
     QImage grab();
 
-    static QWindow *renderWindowFor(QQuickWindow *win, QPoint *offset = 0);
-    virtual QWindow *renderWindow(QPoint *offset) { Q_UNUSED(offset); return 0; }
+    static QWindow *renderWindowFor(QQuickWindow *win, QPoint *offset = Q_NULLPTR);
+    virtual QWindow *renderWindow(QPoint *offset) { Q_UNUSED(offset); return Q_NULLPTR; }
 
 Q_SIGNALS:
     void renderRequested();
diff --git a/src/quick/items/qquickview.h b/src/quick/items/qquickview.h
index 80da0ba4f1..28be948ff4 100644
--- a/src/quick/items/qquickview.h
+++ b/src/quick/items/qquickview.h
@@ -54,9 +54,9 @@ class Q_QUICK_EXPORT QQuickView : public QQuickWindow
     Q_PROPERTY(Status status READ status NOTIFY statusChanged)
     Q_PROPERTY(QUrl source READ source WRITE setSource DESIGNABLE true)
 public:
-    explicit QQuickView(QWindow *parent = 0);
+    explicit QQuickView(QWindow *parent = Q_NULLPTR);
     QQuickView(QQmlEngine* engine, QWindow *parent);
-    QQuickView(const QUrl &source, QWindow *parent = 0);
+    QQuickView(const QUrl &source, QWindow *parent = Q_NULLPTR);
     virtual ~QQuickView();
 
     QUrl source() const;
diff --git a/src/quick/items/qquickwindow.h b/src/quick/items/qquickwindow.h
index d4ffb100de..92c560644e 100644
--- a/src/quick/items/qquickwindow.h
+++ b/src/quick/items/qquickwindow.h
@@ -89,7 +89,7 @@ public:
     };
     Q_ENUM(SceneGraphError)
 
-    QQuickWindow(QWindow *parent = 0);
+    QQuickWindow(QWindow *parent = Q_NULLPTR);
     explicit QQuickWindow(QQuickRenderControl *renderControl);
 
     virtual ~QQuickWindow();
@@ -123,7 +123,7 @@ public:
     // Scene graph specific functions
     QSGTexture *createTextureFromImage(const QImage &image) const;
     QSGTexture *createTextureFromImage(const QImage &image, CreateTextureOptions options) const;
-    QSGTexture *createTextureFromId(uint id, const QSize &size, CreateTextureOptions options = CreateTextureOption(0)) const;
+    QSGTexture *createTextureFromId(uint id, const QSize &size, CreateTextureOptions options = CreateTextureOption()) const;
 
     void setClearBeforeRendering(bool enabled);
     bool clearBeforeRendering() const;
@@ -170,7 +170,7 @@ public Q_SLOTS:
     void releaseResources();
 
 protected:
-    QQuickWindow(QQuickWindowPrivate &dd, QWindow *parent = 0);
+    QQuickWindow(QQuickWindowPrivate &dd, QWindow *parent = Q_NULLPTR);
 
     void exposeEvent(QExposeEvent *) Q_DECL_OVERRIDE;
     void resizeEvent(QResizeEvent *) Q_DECL_OVERRIDE;
diff --git a/src/quick/scenegraph/coreapi/qsgabstractrenderer.h b/src/quick/scenegraph/coreapi/qsgabstractrenderer.h
index 2f7da6f610..2b13f94bc8 100644
--- a/src/quick/scenegraph/coreapi/qsgabstractrenderer.h
+++ b/src/quick/scenegraph/coreapi/qsgabstractrenderer.h
@@ -80,7 +80,7 @@ Q_SIGNALS:
     void sceneGraphChanged();
 
 protected:
-    QSGAbstractRenderer(QObject *parent = 0);
+    QSGAbstractRenderer(QObject *parent = Q_NULLPTR);
     virtual void nodeChanged(QSGNode *node, QSGNode::DirtyState state) = 0;
 
 private:
diff --git a/src/quick/scenegraph/coreapi/qsgnode.h b/src/quick/scenegraph/coreapi/qsgnode.h
index 4c9ae7251e..f73fcdacf2 100644
--- a/src/quick/scenegraph/coreapi/qsgnode.h
+++ b/src/quick/scenegraph/coreapi/qsgnode.h
@@ -145,7 +145,7 @@ public:
 
     QT_DEPRECATED void clearDirty() { }
     void markDirty(DirtyState bits);
-    QT_DEPRECATED DirtyState dirtyState() const { return 0; }
+    QT_DEPRECATED DirtyState dirtyState() const { return Q_NULLPTR; }
 
     virtual bool isSubtreeBlocked() const;
 
diff --git a/src/quick/scenegraph/util/qsgengine.h b/src/quick/scenegraph/util/qsgengine.h
index 325d3a9ca2..f49561d4b0 100644
--- a/src/quick/scenegraph/util/qsgengine.h
+++ b/src/quick/scenegraph/util/qsgengine.h
@@ -57,15 +57,15 @@ public:
     };
     Q_DECLARE_FLAGS(CreateTextureOptions, CreateTextureOption)
 
-    QSGEngine(QObject *parent = 0);
+    QSGEngine(QObject *parent = Q_NULLPTR);
     ~QSGEngine();
 
     void initialize(QOpenGLContext *context);
     void invalidate();
 
     QSGAbstractRenderer *createRenderer() const;
-    QSGTexture *createTextureFromImage(const QImage &image, CreateTextureOptions options = CreateTextureOption(0)) const;
-    QSGTexture *createTextureFromId(uint id, const QSize &size, CreateTextureOptions options = CreateTextureOption(0)) const;
+    QSGTexture *createTextureFromImage(const QImage &image, CreateTextureOptions options = CreateTextureOption()) const;
+    QSGTexture *createTextureFromId(uint id, const QSize &size, CreateTextureOptions options = CreateTextureOption()) const;
 };
 
 QT_END_NAMESPACE
diff --git a/src/quick/util/qquickimageprovider.h b/src/quick/util/qquickimageprovider.h
index cc03eb0fa0..9ecedf60ad 100644
--- a/src/quick/util/qquickimageprovider.h
+++ b/src/quick/util/qquickimageprovider.h
@@ -81,7 +81,7 @@ Q_SIGNALS:
 class Q_QUICK_EXPORT QQuickImageProvider : public QQmlImageProviderBase
 {
 public:
-    QQuickImageProvider(ImageType type, Flags flags = 0);
+    QQuickImageProvider(ImageType type, Flags flags = Flags());
     virtual ~QQuickImageProvider();
 
     ImageType imageType() const;
diff --git a/src/quickwidgets/qquickwidget.h b/src/quickwidgets/qquickwidget.h
index 5bb6b49a49..236a4a9c27 100644
--- a/src/quickwidgets/qquickwidget.h
+++ b/src/quickwidgets/qquickwidget.h
@@ -58,9 +58,9 @@ class Q_QUICKWIDGETS_EXPORT QQuickWidget : public QWidget
     Q_PROPERTY(QUrl source READ source WRITE setSource DESIGNABLE true)
 
 public:
-    explicit QQuickWidget(QWidget *parent = 0);
+    explicit QQuickWidget(QWidget *parent = Q_NULLPTR);
     QQuickWidget(QQmlEngine* engine, QWidget *parent);
-    QQuickWidget(const QUrl &source, QWidget *parent = 0);
+    QQuickWidget(const QUrl &source, QWidget *parent = Q_NULLPTR);
     virtual ~QQuickWidget();
 
     QUrl source() const;