Pure virtual slots qt





Q_core_export const char *qFlagLocation(const char *method #ifndef QT_NO_debug # define qlocation "0" _file_ qtostring line # define slot(a) qFlagLocation 1 a qlocation) # define signal(a) qFlagLocation 2 a qlocation) #else # define slot(a) "1 a # define signal(a) "2 a #endif Those macros just use.
New features have been added and a lot happened under the hood.
The connect statement looks like this: connect( sender, signal( signal receiver, slot( slot where sender and receiver are pointers to QObjects and where signal and slot are function signatures without parameter names.
To successfully connect a signal to a slot (or to another signal they must have the same parameter types in the same order: connect(ftp, signal(rawCommandReply(int, const QString this, slot(processReply(int, const QString Exceptionally, if a signal has more parameters than the slot it is connected.In this case we have 2 methods, and the methods description starts at index.QMetaObject :connect(obj, signalId, this, slotId QObject:metaObject - methodCount Finally, we register the connection with membrasin bonus-apteekki Qt's meta-object system.The QMetaObject is initialized with the meta object of the parent object (QObject:staticMetaObject in this case) as superdata.Resolving the (dynamic) slot is a bit more work: int slotId lue(theSlot, -1 if (slotId -1) slotId ze slotIndicestheSlot slotId; We check whether the slot signature has been registered before in the same DynamicQObject instance.Qt 4's meta-object system makes this sort of extension possible, with a little bit of hackery.If all goes well, we invoke the specified slot (using DynamicSlot:call and return -1 to indicate that the metacall has been processed.MySalary) mySalary newSalary; emit salaryChanged(mySalary Notice how the setSalary slot is implemented.If the signal was not found, we return false.
Download source code, expanding the Q_object Macro.The mechanism can be used by any QObject subclass: class Employee : public QObject, q_object public: Employee mySalary 0; int salary const return mySalary; public slots: void setSalary(int newSalary signals: void salaryChanged(int newSalary private: int mySalary; ; void Employee:setSalary(int newSalary) if (newSalary!The reason for this is that the meta-object system expects the number of methods declared in a meta-object to be static.QString tr(const char *sourceText, const char *comment 0 static.But all the slots waste space in the vector and there are usually more slots than signals in an object.String Table struct QByteArrayData 6; char 46; ; #define QT_MOC_literal(idx, ofs, len) qptrdiff (offsetof( qt_meta_stringdata_Counter_t, stringdata0) ofs - idx * sizeof( QByteArrayData ) ) static const qt_meta_stringdata_Counter_t QT_MOC_literal(0, 0, 7 / "Counter" QT_MOC_literal(1, 8, 12 / "valueChanged" QT_MOC_literal(2, 21, 0 / " QT_MOC_literal(3, 22,.In the case of a slot invocation, the identifier must be a valid identifier for the DynamicQObject object.

They are becoming public in Qt5 in order to enable the new syntax.
This will remove meaningless whitespace in the signatures, making it possible for us to recognize them.
Data, qt_meta_data_Counter, qt_static_metacall, Q_nullptr, Q_nullptr ; const QMetaObject *Counter const return QObject : d_ptr -?


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