PyQt, main window can't have reference to application class

[Sibylle Koczian]

Phil Thompson schrieb:
> On Monday 24 May 2004 3:54 pm, Sibylle Koczian wrote:
> 
>>Still trying to learn PyQt from a book about several Python GUI
>>toolkits, I seem to learn first what doesn't work. The following small
>>script seems to work, but after closing the window I get the error
>>message "Fatal Python error: PyEval_RestoreThread: NULL tstate".
> 
> 
> You have created a circular reference which won't help. The problem doesn't 
> occur if PyQt is built with SIP v4 - it uses the newer Python thread API.
>
But the circular reference would remain, wouldn't it? I still don't see 
a way around it: the main window must know about the GUI independent 
methods of the application, and those methods should be able to exchange 
data with the main window. But I still want to keep the GUI independent 
things separate.

> 
>>Without the line "self.app = app" the error goes away. So I suppose the
>>main window can't have a reference to the application class. Right?
>>Using the global variable qApp instead of self.app doesn't work either:
>>qApp seems to be an instance of QApplication, not an instance of HelloApp.
> 
> 
> It's the same C++ instance, but they are different types. knopftext is an 
> attribute of the HelloApp type. qApp is of type QApplication.
> 
That's what I meant.

Thank you,
Koczian

-- 
Dr. Sibylle Koczian
Universitaetsbibliothek, Abt. Naturwiss.
D-86135 Augsburg

Tel.: (0821) 598-2400, Fax : (0821) 598-2410
e-mail : Sibylle.Koczian at Bibliothek.Uni-Augsburg.DE