qobject_cast on a base class

[bunjee]

Hey guys, I have the following class:

class myWidget : public QObject, public myInterface

class myWidget : public QObject, public myInterface

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- Now I'm in myInterface::myFunction()
- I want to cast "this" into myWidget:

qobject_cast<myWidget *> (this);

qobject_cast<myWidget *> (this);

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This doesn't seem to work anyone knows why?

[wysota]

Do you have Q_OBJECT macro in your class?

[bunjee]

Let me clarify what I was trying to do:

I have a myAbstractClass supposed to be used like that :

class myObject : public QObject, public myAbstractClass

class myObject : public QObject, public myAbstractClass

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But,

In my library, I'm not defining the myObject class, just the myAstractClass.

It's "supposed" to be used with a QObject all the time to have the benefit of parency. (which is a bad design at this point).

So I wanted to qobject_cast that base class in QObject assuming it was inheriting QObject.

In that "ugly" case I guess dynamic_cast is my only option.

[wysota]

Use Q_DECLARE_INTERFACE in myAbstractClass. Then you'll be able to use object_cast. And remember about Q_OBJECT in the subclass.