QMetaType: Automatic registration of Q_GADGET and Q_ENUM types

Change-Id: If43dcc2b77fea5ae3ec40cc847467fc21fbd2c83
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Reviewed-by: Simon Hausmann <simon.hausmann@theqtcompany.com>

2 files changed, 67 insertions, 3 deletions

diff --git a/src/corelib/kernel/qmetatype.h b/src/corelib/kernel/qmetatype.h
index 025fbb6372..b743e78890 100644
--- a/src/corelib/kernel/qmetatype.h
+++ b/src/corelib/kernel/qmetatype.h
@@ -1545,7 +1545,10 @@ namespace QtPrivate
     Q_CORE_EXPORT bool isBuiltinType(const QByteArray &type);
 } // namespace QtPrivate
 
-template <typename T, bool = QtPrivate::IsPointerToTypeDerivedFromQObject<T>::Value>
+template <typename T, int =
+    QtPrivate::IsPointerToTypeDerivedFromQObject<T>::Value ? QMetaType::PointerToQObject :
+    QtPrivate::IsGadgetHelper<T>::Value                    ? QMetaType::IsGadget :
+    QtPrivate::IsQEnumHelper<T>::Value                     ? QMetaType::IsEnumeration : 0>
 struct QMetaTypeIdQObject
 {
     enum {
@@ -1725,8 +1728,9 @@ QT_DEPRECATED inline Q_DECL_CONSTEXPR int qRegisterMetaType(T *)
 #endif
 #endif
 
+#ifndef QT_NO_QOBJECT
 template <typename T>
-struct QMetaTypeIdQObject<T*, /* isPointerToTypeDerivedFromQObject */ true>
+struct QMetaTypeIdQObject<T*, QMetaType::PointerToQObject>
 {
     enum {
         Defined = 1
@@ -1749,6 +1753,53 @@ struct QMetaTypeIdQObject<T*, /* isPointerToTypeDerivedFromQObject */ true>
     }
 };
 
+template <typename T>
+struct QMetaTypeIdQObject<T, QMetaType::IsGadget>
+{
+    enum {
+        Defined = 1
+    };
+
+    static int qt_metatype_id()
+    {
+        static QBasicAtomicInt metatype_id = Q_BASIC_ATOMIC_INITIALIZER(0);
+        if (const int id = metatype_id.loadAcquire())
+            return id;
+        const char * const cName = T::staticMetaObject.className();
+        const int newId = qRegisterNormalizedMetaType<T>(
+            cName,
+            reinterpret_cast<T*>(quintptr(-1)));
+        metatype_id.storeRelease(newId);
+        return newId;
+    }
+};
+
+template <typename T>
+struct QMetaTypeIdQObject<T, QMetaType::IsEnumeration>
+{
+    enum {
+        Defined = 1
+    };
+
+    static int qt_metatype_id()
+    {
+        static QBasicAtomicInt metatype_id = Q_BASIC_ATOMIC_INITIALIZER(0);
+        if (const int id = metatype_id.loadAcquire())
+            return id;
+        const char *eName = qt_getEnumName(T());
+        const char *cName = qt_getEnumMetaObject(T())->className();
+        QByteArray typeName;
+        typeName.reserve(int(strlen(cName) + 2 + strlen(eName)));
+        typeName.append(cName).append("::").append(eName);
+        const int newId = qRegisterNormalizedMetaType<T>(
+            typeName,
+            reinterpret_cast<T*>(quintptr(-1)));
+        metatype_id.storeRelease(newId);
+        return newId;
+    }
+};
+#endif
+
 #ifndef QT_NO_DATASTREAM
 template <typename T>
 inline int qRegisterMetaTypeStreamOperators()
diff --git a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
index 8da96c0977..717a7633f5 100644
--- a/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
+++ b/tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp
@@ -136,6 +136,11 @@ public:
       : QObject(parent)
     {
     }
+    enum CustomQEnum { Val1, Val2 };
+    Q_ENUM(CustomQEnum)
+};
+class CustomGadget {
+    Q_GADGET
 };
 
 class CustomNonQObject {};
@@ -146,10 +151,13 @@ void tst_QMetaType::defined()
     QCOMPARE(int(QMetaTypeId2<Foo>::Defined), 0);
     QCOMPARE(int(QMetaTypeId2<void*>::Defined), 1);
     QCOMPARE(int(QMetaTypeId2<int*>::Defined), 0);
-    QVERIFY(QMetaTypeId2<CustomQObject*>::Defined);
+    QCOMPARE(int(QMetaTypeId2<CustomQObject::CustomQEnum>::Defined), 1);
+    QCOMPARE(int(QMetaTypeId2<CustomGadget>::Defined), 1);
+    QVERIFY(int(QMetaTypeId2<CustomQObject*>::Defined));
     QVERIFY(!QMetaTypeId2<CustomQObject>::Defined);
     QVERIFY(!QMetaTypeId2<CustomNonQObject>::Defined);
     QVERIFY(!QMetaTypeId2<CustomNonQObject*>::Defined);
+    QVERIFY(!QMetaTypeId2<CustomGadget*>::Defined);
 }
 
 struct Bar
@@ -378,6 +386,11 @@ void tst_QMetaType::typeName_data()
     QTest::newRow("QMap<int,int>") << static_cast<QMetaType::Type>(::qMetaTypeId<QMap<int, int> >()) << QString::fromLatin1("QMap<int,int>");
     QTest::newRow("QVector<QList<int>>") << static_cast<QMetaType::Type>(::qMetaTypeId<QVector<QList<int> > >()) << QString::fromLatin1("QVector<QList<int> >");
     QTest::newRow("QVector<QMap<int,int>>") << static_cast<QMetaType::Type>(::qMetaTypeId<QVector<QMap<int, int> > >()) << QString::fromLatin1("QVector<QMap<int,int> >");
+
+    QTest::newRow("CustomQObject*") << static_cast<QMetaType::Type>(::qMetaTypeId<CustomQObject*>()) << QString::fromLatin1("CustomQObject*");
+    QTest::newRow("CustomGadget") << static_cast<QMetaType::Type>(::qMetaTypeId<CustomGadget>()) << QString::fromLatin1("CustomGadget");
+    QTest::newRow("CustomQObject::CustomQEnum") << static_cast<QMetaType::Type>(::qMetaTypeId<CustomQObject::CustomQEnum>()) << QString::fromLatin1("CustomQObject::CustomQEnum");
+    QTest::newRow("Qt::ArrowType") << static_cast<QMetaType::Type>(::qMetaTypeId<Qt::ArrowType>()) << QString::fromLatin1("Qt::ArrowType");
 }
 
 void tst_QMetaType::typeName()