Hello, you can use a custom type with QVariant by declaring it using Q_DECLARE_METATYPE ( Type ). Hope that helps.
Regrads, Sven 2013/4/5 Pritam Ghanghas <pritam_ghang...@infosys.com> > QObjects are not supposed to be copiable, providing a copy constructor > violates Qt's principle that QObject is an identity type. If you want to > store QObjects in QVariant store pointers to be them instead. > ________________________________ > From: > interest-bounces+pritam_ghanghas=infosys....@qt-project.org[interest-bounces+pritam_ghanghas= > infosys....@qt-project.org] on behalf of Aekold Helbrass [ > helbr...@gmail.com] > Sent: Friday, April 05, 2013 1:31 PM > To: Samuel Gaist > Cc: Qt-interest Interest > Subject: Re: [Interest] QVariant cannot take custom type > > I've provided copy-constructor, as was suggested in that article. > > > On Fri, Apr 5, 2013 at 10:50 AM, Samuel Gaist <samuel.ga...@edeltech.ch > <mailto:samuel.ga...@edeltech.ch>> wrote: > Hi, > > IIRC, you can't have Item or Holder in a QVariant because there QObject so > the copy constructor is disabled for them. > > This thread might be of interest > http://stackoverflow.com/questions/7872578/how-to-properly-use-qregistermetatype-on-a-class-derived-from-qobject > > Hope it helps > > On 5 avr. 2013, at 09:37, Aekold Helbrass wrote: > > > Hi All! > > > > Short story is: I'm trying to put custom type into QVariant and it > doesn't work, on debug I see QVariant with value <not accessible> and > trying to read it I'm getting segfault. > > > > Long story, I'm new to Qt/C++ so I'm trying to do everything very > carefully, but I'm almost sure it's some rookie mistake in my code. This > code started as attempt to bind JSON tree to object tree, and stopped on > reading of QList, because QMetaProperty wants QVariant. > > > > Source code: > > ================ main.cpp ==================== > > #include <QCoreApplication> > > #include <QObject> > > #include <QList> > > #include <QMetaType> > > #include <QMetaObject> > > #include <QMetaProperty> > > #include <QDebug> > > > > #include "item.h" > > #include "holder.h" > > > > Q_DECLARE_METATYPE(Item) > > Q_DECLARE_METATYPE(Item*) > > Q_DECLARE_METATYPE(Holder) > > > > int main(int argc, char *argv[]) { > > QCoreApplication a(argc, argv); > > > > int typeItem = qRegisterMetaType<Item>("Item"); > > int typeHolder = qRegisterMetaType<Holder>("Holder"); > > int typeItemList = qRegisterMetaType<QList<Item*> >("QList<Item*>>"); > > int typeItemPointer = qRegisterMetaType<Item*>("Item*"); > > > > QList<QVariant> list; > > for (int i = 0; i < 10; i++) { > > void* created = QMetaType::create(typeItem); > > Item* item = static_cast<Item*>(created); > > item->setName("item " + i); > > // attempt 1: > > QVariant var(typeItem, created); > > // attempt 2: > > //QVariant var; > > //var.setValue(item); > > // attempt 3: > > //QVariant var = QVariant::fromValue(item); > > list.append(var); > > } > > > > Holder* holder = new Holder(); > > int index = holder->metaObject()->indexOfProperty("items"); > > QMetaProperty property = holder->metaObject()->property(index); > > property.write(holder, list); > > > > QList<Item*> items = holder->items(); > > for (int i = 0; i < items.size(); i++) { > > Item* item = items.at<http://items.at>(i); > > qDebug() << "name: " << item->name(); > > } > > > > return a.exec(); > > } > > > > ======================================= holder.h > =============================== > > #ifndef HOLDER_H > > #define HOLDER_H > > > > > > #include <QObject> > > > > #include <QList> > > #include "item.h" > > > > class Holder : public QObject { > > > > Q_OBJECT > > Q_PROPERTY(QList<Item*> items READ items WRITE setItems) > > > > public: > > Holder(QObject* parent=0) : QObject(parent) {} > > > > Holder(const Holder& copy, QObject* parent=0) : QObject(parent) { > > > > pItems = copy.items(); > > > > } > > Holder& operator =(const Holder& value) { > > > > pItems = value.items(); > > > > } > > QList<Item*> items() const { > > > > return pItems; > > > > } > > public slots: > > > > void setItems(const QList<Item*>& value) { > > > > pItems = value; > > > > } > > private: > > > > QList<Item*> pItems; > > > > }; > > > > #endif // HOLDER_H > > > > > > > > ============================== item.h ================================ > > #ifndef ITEM_H > > > > #define ITEM_H > > > > #include <QObject> > > > > class Item : public QObject { > > > > Q_OBJECT > > Q_PROPERTY(QString name READ name WRITE setName) > > > > public: > > Item(QObject* parent=0) : QObject(parent) {} > > > > Item(const Item& copy, QObject* parent=0) : QObject(parent) { > > > > pName = copy.name<http://copy.name>(); > > > > } > > Item& operator =(const Item& value) { > > > > pName = value.name<http://value.name>(); > > > > } > > QString name() const { > > > > return pName; > > > > } > > > > public slots: > > > > void setName(const QString& value) { > > > > pName = value; > > > > } > > private: > > > > QString pName; > > > > }; > > > > #endif // ITEM_H > > > > > > > > ======================== end =================================== > > _______________________________________________ > > Interest mailing list > > Interest@qt-project.org<mailto:Interest@qt-project.org> > > http://lists.qt-project.org/mailman/listinfo/interest > > _______________________________________________ > Interest mailing list > Interest@qt-project.org<mailto:Interest@qt-project.org> > http://lists.qt-project.org/mailman/listinfo/interest > > > **************** CAUTION - Disclaimer ***************** > This e-mail contains PRIVILEGED AND CONFIDENTIAL INFORMATION intended > solely > for the use of the addressee(s). If you are not the intended recipient, > please > notify the sender by e-mail and delete the original message. Further, you > are not > to copy, disclose, or distribute this e-mail or its contents to any other > person and > any such actions are unlawful. This e-mail may contain viruses. Infosys > has taken > every reasonable precaution to minimize this risk, but is not liable for > any damage > you may sustain as a result of any virus in this e-mail. You should carry > out your > own virus checks before opening the e-mail or attachment. Infosys reserves > the > right to monitor and review the content of all messages sent to or from > this e-mail > address. Messages sent to or from this e-mail address may be stored on the > Infosys e-mail system. > ***INFOSYS******** End of Disclaimer ********INFOSYS*** > _______________________________________________ > Interest mailing list > Interest@qt-project.org > http://lists.qt-project.org/mailman/listinfo/interest >
_______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
