Compiler error when calling QObject::connect. What am I missing?

I have encountered a strange compiler error when trying to connect a QGraphicsView's QScrollBar to a slot in my own class.
The code is as follows (simplified):

Code:

---

MyClass::MyClass(QWidget * parent, Qt::WindowFlags f): QDialog(parent, f)
{
    _widget.setupUi(this);
 
    _imageScene = new QGraphicsScene;
 
    _widget.graphicsView->setScene(_imageScene);
 
    //This works
    connect(_widget.imageListView->selectionModel(),    SIGNAL(currentChanged(const QModelIndex&, const QModelIndex&)), this, SLOT(currentImageChanged(const QModelIndex&)));
 
    //These two are causing the compiler errors
    connect(_widget.graphicsView->horizontalScrollBar(),   SIGNAL(valueChanged(int)),  this, SLOT(updateVisibleRect()));
    connect(_widget.graphicsView->verticalScrollBar(),     SIGNAL(valueChanged(int)),  this, SLOT(updateVisibleRect()));
}

---

I didn't forget the Q_OBJECT declaration and the updateVisibleRect() is declared as a slot just like the other slots I have in the class.
There are a couple of other connects in the constructor I omitted. But they are working just fine. Only if I try to connect the QGraphicsView's scroll bars to my slots, there is a compiler error:

Code:

---

src/MyClass.cpp:58: error: no matching function for call to `MyClass::connect(QScrollBar*, const char*, MyClass* const, const char*)'
 
d:/Programme/Qt/2009.04/qt/include/QtCore/../../src/corelib/kernel/qobject.h:202: note: candidates are: static bool QObject::connect(const QObject*, const char*, const QObject*, const char*, Qt::ConnectionType)
 
d:/Programme/Qt/2009.04/qt/include/QtCore/../../src/corelib/kernel/qobject.h:308: note:                 bool QObject::connect(const QObject*, const char*, const char*, Qt::ConnectionType) const
 
src/MyClass.cpp:59: error: no matching function for call to `MyClass::connect(QScrollBar*, const char*, FATThresholdDialog* const, const char*)'
 
d:/Programme/Qt/2009.04/qt/include/QtCore/../../src/corelib/kernel/qobject.h:202: note: candidates are: static bool QObject::connect(const QObject*, const char*, const QObject*, const char*, Qt::ConnectionType)
 
d:/Programme/Qt/2009.04/qt/include/QtCore/../../src/corelib/kernel/qobject.h:308: note:                 bool QObject::connect(const QObject*, const char*, const char*, Qt::ConnectionType) const

---

It seems to me that there is a problem with the type returned by QGraphicsView::horizontalScrollBar().
Strangely, connecting the selectionModel of a QListView I'm also using to one of my slots works just fine.

Is there something I am missing? Any ideas on what causes the error?

Thanks in advance

Someone With A Question

Post Deleted

Did you include the header for QScrollBar in your class?

Quote:

---

Originally Posted by rexi

Did you include the header for QScrollBar in your class?

---

That seemed to be the reason. Thanks :)

A little strange the compiler didn't complain about unresolved type or sth like that.

It doesn't have to, because you're passing a pointer to it, which at that point is a resolved type. At that point it just doesn't know the QScrollBar is a QObject.