[PyKDE] PyQt and trees

[Andreas Pakulat]

On 11.04.06 11:59:10, Bert Rodiers wrote:
> On 4/10/06, Andreas Pakulat <apaku at gmx.de> wrote:
> 
> > This one's easy: The model instance is local to the test function and
> > thus gets garbage collected when test ends. So the Tree doesn't have a
> > model to work with at that point. Changing test to
> >
> > def test(self):
> >   self.model = TreeModel()
> >   self.treeView.setModel(self.model)
> >
> > makes the app work. Or you could make the TreeModel a child of the
> > treeView or some other QObject derived instance that you have. It's just
> > important that at least 1 reference to the created object is available
> > after the function is done so the object is not gc'ed.
> 
> I'm mainly a C++ programmer who recently started experimenting with
> Python. I thought the object wouldn't go out of scope since the
> self.treeView would keep a reference to it, but apparently I was
> mistaken.

On first sight I thought so too. And I believe I had some discussions
with Phil about  <someview>.setModel taking ownership of the model so
there's at least one reference to the model, but I can't remember the
"outcome".

Anyway I guess this is because the normal treeview is only a wrapper
around the c++-class and due to this doesn't store a python reference to
the model that is set.

Andreas

-- 
You own a dog, but you can only feed a cat.