Make QPersistentModelIndex an internal meta-type

It was already a user meta-type, so it only gets
promoted to internal.

[ChangeLog][QtCore] QPersistentModel index becomes an built-in
meta-type, including QVariant support.

Change-Id: I63d733d1eb66aa61691e7afce27fe7372a83ac00
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

src/corelib/itemmodels/qabstractitemmodel.h

@@ -484,6 +484,5 @@ inline uint qHash(const QModelIndex &index) Q_DECL_NOTHROW
 QT_END_NAMESPACE
 
 Q_DECLARE_METATYPE(QModelIndexList)
-Q_DECLARE_METATYPE(QPersistentModelIndex)
 
 #endif // QABSTRACTITEMMODEL_H

src/corelib/kernel/qmetatype.cpp

@@ -277,6 +277,7 @@ struct DefinedTypesFilter {
     \value QJsonArray QJsonArray
     \value QJsonDocument QJsonDocument
     \value QModelIndex QModelIndex
+    \value QPersistentModelIndex QPersistentModelIndex (since 5.5)
     \value QUuid QUuid
     \value QByteArrayList QByteArrayList
 
@@ -1209,6 +1210,7 @@ bool QMetaType::save(QDataStream &stream, int type, const void *data)
     case QMetaType::VoidStar:
     case QMetaType::QObjectStar:
     case QMetaType::QModelIndex:
+    case QMetaType::QPersistentModelIndex:
     case QMetaType::QJsonValue:
     case QMetaType::QJsonObject:
     case QMetaType::QJsonArray:
@@ -1429,6 +1431,7 @@ bool QMetaType::load(QDataStream &stream, int type, void *data)
     case QMetaType::VoidStar:
     case QMetaType::QObjectStar:
     case QMetaType::QModelIndex:
+    case QMetaType::QPersistentModelIndex:
     case QMetaType::QJsonValue:
     case QMetaType::QJsonObject:
     case QMetaType::QJsonArray:

src/corelib/kernel/qmetatype.h

@@ -113,6 +113,7 @@ inline Q_DECL_CONSTEXPR int qMetaTypeId();
     F(QJsonObject, 46, QJsonObject) \
     F(QJsonArray, 47, QJsonArray) \
     F(QJsonDocument, 48, QJsonDocument) \
+    F(QPersistentModelIndex, 50, QPersistentModelIndex) \
 
 #define QT_FOR_EACH_STATIC_CORE_POINTER(F)\
     F(QObjectStar, 39, QObject*)
@@ -407,7 +408,7 @@ public:
         QT_FOR_EACH_STATIC_TYPE(QT_DEFINE_METATYPE_ID)
 
         FirstCoreType = Bool,
-        LastCoreType = QByteArrayList,
+        LastCoreType = QPersistentModelIndex,
         FirstGuiType = QFont,
         LastGuiType = QPolygonF,
         FirstWidgetsType = QSizePolicy,
@@ -431,7 +432,7 @@ public:
         QLocale = 18, QRect = 19, QRectF = 20, QSize = 21, QSizeF = 22,
         QLine = 23, QLineF = 24, QPoint = 25, QPointF = 26, QRegExp = 27,
         QEasingCurve = 29, QUuid = 30, QVariant = 41, QModelIndex = 42,
-        QRegularExpression = 44,
+        QPersistentModelIndex = 50, QRegularExpression = 44,
         QJsonValue = 45, QJsonObject = 46, QJsonArray = 47, QJsonDocument = 48,
         QByteArrayList = 49, QObjectStar = 39, SChar = 40,
         Void = 43,

src/corelib/kernel/qmetatype_p.h

@@ -192,6 +192,7 @@ template<> struct TypeDefinition<QJsonDocument> { static const bool IsAvailable
 template<> struct TypeDefinition<QJsonObject> { static const bool IsAvailable = false; };
 template<> struct TypeDefinition<QJsonValue> { static const bool IsAvailable = false; };
 template<> struct TypeDefinition<QModelIndex> { static const bool IsAvailable = false; };
+template<> struct TypeDefinition<QPersistentModelIndex> { static const bool IsAvailable = false; };
 template<> struct TypeDefinition<QUrl> { static const bool IsAvailable = false; };
 template<> struct TypeDefinition<QByteArrayList> { static const bool IsAvailable = false; };
 #endif

src/corelib/kernel/qvariant.cpp

@@ -390,7 +390,25 @@ static bool convert(const QVariant::Private *d, int t, void *result, bool *ok)
             return false;
         }
         break;
-#endif
+    case QVariant::ModelIndex:
+        switch (d->type) {
+        case QVariant::PersistentModelIndex:
+            *static_cast<QModelIndex *>(result) = QModelIndex(*v_cast<QPersistentModelIndex>(d));
+            break;
+        default:
+            return false;
+        }
+        break;
+    case QVariant::PersistentModelIndex:
+        switch (d->type) {
+        case QVariant::ModelIndex:
+            *static_cast<QPersistentModelIndex *>(result) = QPersistentModelIndex(*v_cast<QModelIndex>(d));
+            break;
+        default:
+            return false;
+        }
+        break;
+#endif // QT_BOOTSTRAPPED
     case QVariant::String: {
         QString *str = static_cast<QString *>(result);
         switch (d->type) {
@@ -1208,6 +1226,7 @@ Q_CORE_EXPORT void QVariantPrivate::registerHandler(const int /* Modules::Names
     \value EasingCurve a QEasingCurve
     \value Uuid a QUuid
     \value ModelIndex a QModelIndex
+    \value PersistentModelIndex a QPersistentModelIndex (since 5.5)
     \value Font  a QFont
     \value Hash a QVariantHash
     \value Icon  a QIcon
@@ -1455,7 +1474,14 @@ QVariant::QVariant(const char *val)
     \since 5.0
     \fn QVariant::QVariant(const QModelIndex &val)
 
-    Constructs a new variant with an modelIndex value, \a val.
+    Constructs a new variant with a QModelIndex value, \a val.
+*/
+
+/*!
+    \since 5.5
+    \fn QVariant::QVariant(const QPersistentModelIndex &val)
+
+    Constructs a new variant with a QPersistentModelIndex value, \a val.
 */
 
 /*!
@@ -1763,6 +1789,9 @@ QVariant::QVariant(const QUuid &uuid)
 QVariant::QVariant(const QModelIndex &modelIndex)
     : d(ModelIndex)
 { v_construct<QModelIndex>(&d, modelIndex); }
+QVariant::QVariant(const QPersistentModelIndex &modelIndex)
+    : d(PersistentModelIndex)
+{ v_construct<QPersistentModelIndex>(&d, modelIndex); }
 QVariant::QVariant(const QJsonValue &jsonValue)
     : d(QMetaType::QJsonValue)
 { v_construct<QJsonValue>(&d, jsonValue); }
@@ -2492,13 +2521,26 @@ QUuid QVariant::toUuid() const
     Returns the variant as a QModelIndex if the variant has userType() \l
     QModelIndex; otherwise returns a default constructed QModelIndex.
 
-    \sa canConvert(), convert()
+    \sa canConvert(), convert(), toPersistentModelIndex()
 */
 QModelIndex QVariant::toModelIndex() const
 {
     return qVariantToHelper<QModelIndex>(d, handlerManager);
 }
 
+/*!
+    \since 5.5
+
+    Returns the variant as a QPersistentModelIndex if the variant has userType() \l
+    QPersistentModelIndex; otherwise returns a default constructed QPersistentModelIndex.
+
+    \sa canConvert(), convert(), toModelIndex()
+*/
+QModelIndex QVariant::toPersistentModelIndex() const
+{
+    return qVariantToHelper<QPersistentModelIndex>(d, handlerManager);
+}
+
 /*!
     \since 5.0
 
@@ -2966,6 +3008,10 @@ static bool canConvertMetaObject(int fromId, int toId, QObject *fromObject)
 */
 bool QVariant::canConvert(int targetTypeId) const
 {
+    if ((targetTypeId == QMetaType::QModelIndex && d.type == QMetaType::QPersistentModelIndex)
+        || (targetTypeId == QMetaType::QPersistentModelIndex && d.type == QMetaType::QModelIndex))
+        return true;
+
     if (targetTypeId == QMetaType::QVariantList
             && (d.type == QMetaType::QVariantList
               || d.type == QMetaType::QStringList

src/corelib/kernel/qvariant.h

@@ -156,6 +156,7 @@ class Q_CORE_EXPORT QVariant
         EasingCurve = QMetaType::QEasingCurve,
         Uuid = QMetaType::QUuid,
         ModelIndex = QMetaType::QModelIndex,
+        PersistentModelIndex = QMetaType::QPersistentModelIndex,
         LastCoreType = QMetaType::LastCoreType,
 
         Font = QMetaType::QFont,
@@ -245,6 +246,7 @@ class Q_CORE_EXPORT QVariant
     QVariant(const QEasingCurve &easing);
     QVariant(const QUuid &uuid);
     QVariant(const QModelIndex &modelIndex);
+    QVariant(const QPersistentModelIndex &modelIndex);
     QVariant(const QJsonValue &jsonValue);
     QVariant(const QJsonObject &jsonObject);
     QVariant(const QJsonArray &jsonArray);
@@ -318,6 +320,7 @@ class Q_CORE_EXPORT QVariant
     QEasingCurve toEasingCurve() const;
     QUuid toUuid() const;
     QModelIndex toModelIndex() const;
+    QModelIndex toPersistentModelIndex() const;
     QJsonValue toJsonValue() const;
     QJsonObject toJsonObject() const;
     QJsonArray toJsonArray() const;

tests/auto/corelib/kernel/qmetatype/tst_qmetatype.cpp

@@ -661,6 +661,9 @@ template<> struct TestValueFactory<QMetaType::QUuid> {
 template<> struct TestValueFactory<QMetaType::QModelIndex> {
     static QModelIndex *create() { return new QModelIndex(); }
 };
+template<> struct TestValueFactory<QMetaType::QPersistentModelIndex> {
+    static QPersistentModelIndex *create() { return new QPersistentModelIndex(); }
+};
 template<> struct TestValueFactory<QMetaType::QRegExp> {
     static QRegExp *create()
     {
@@ -1735,6 +1738,7 @@ struct StreamingTraits
 DECLARE_NONSTREAMABLE(void)
 DECLARE_NONSTREAMABLE(void*)
 DECLARE_NONSTREAMABLE(QModelIndex)
+DECLARE_NONSTREAMABLE(QPersistentModelIndex)
 DECLARE_NONSTREAMABLE(QJsonValue)
 DECLARE_NONSTREAMABLE(QJsonObject)
 DECLARE_NONSTREAMABLE(QJsonArray)

tests/auto/corelib/kernel/qvariant/tst_qvariant.cpp

@@ -248,6 +248,7 @@ private slots:
     void movabilityTest();
     void variantInVariant();
     void userConversion();
+    void modelIndexConversion();
 
     void forwardDeclare();
     void debugStream_data();
@@ -3846,6 +3847,17 @@ void tst_QVariant::userConversion()
     }
 }
 
+void tst_QVariant::modelIndexConversion()
+{
+    QVariant modelIndexVariant = QModelIndex();
+    QVERIFY(modelIndexVariant.canConvert(QMetaType::QPersistentModelIndex));
+    QVERIFY(modelIndexVariant.convert(QMetaType::QPersistentModelIndex));
+    QCOMPARE(modelIndexVariant.type(), QVariant::PersistentModelIndex);
+    QVERIFY(modelIndexVariant.canConvert(QMetaType::QModelIndex));
+    QVERIFY(modelIndexVariant.convert(QMetaType::QModelIndex));
+    QCOMPARE(modelIndexVariant.type(), QVariant::ModelIndex);
+}
+
 class Forward;
 Q_DECLARE_OPAQUE_POINTER(Forward*)
 Q_DECLARE_METATYPE(Forward*)
@@ -4073,6 +4085,7 @@ void tst_QVariant::implicitConstruction()
     F(EasingCurve) \
     F(Uuid) \
     F(ModelIndex) \
+    F(PersistentModelIndex) \
     F(RegularExpression) \
     F(JsonValue) \
     F(JsonObject) \