[PyQt] Bug in QTableView.setModel()

[Aaron Digulla]

Quoting Aaron Digulla <digulla at hepe.com>:

>>> I'm talking about preventing the python class which is used as the model
>>> being garbage collected; it doesn't matter from which Qt class it is
>>> derived.
>>>
>>> As it is, the class pointer is copied into the view class and then python
>>> frees the memory. That causes spurious display errors and crashes. No
>>> matter how you look at it, that's a bug.
>>
>> No its not, the view doesn't take ownership of the model, neither in Qt
>> C++ nor in PyQt, thats why your object is garbage collected. A reason
>> for not taking ownership is that a model might be used in multiple
>> views.
>
> Incrementing the usage count != ownership. I'm the one who decides
> which object in my project "owns" the model. This is a design issue.

Here is another case which argues against you:

I have a QTextEdit which uses several QTestDocument's (so one view has  
several models, depending on what is selected in the UI). There is one  
use case where I have no model (ie. the selected element just doesn't  
have any text attached).

So what I did was:

     if scene is None:
         edit.setDocument(QTextDocument())
         edit.setEnabled(False)
         return

and guess what: I got spurious crashes because the object returned by  
QTextDocument() is GC'd. Where am I supposed to store this model? It's  
not related to *any* object in my project. It's just a dummy so the  
user doesn't accidentally edit the last selected text.

So all in all, I can't agree to your argumentation. Please fix these  
bugs. Is there an issue tracker somewhere where can I add these issues?

Regards,

-- 
Aaron "Optimizer" Digulla a.k.a. Philmann Dark
"It's not the universe that's limited, it's our imagination.
Follow me and I'll show you something beyond the limits."
http://www.pdark.de/