[PyKDE] Model indexes and internal pointers

[Arve Knudsen]

Phil, did you reach any conclusion on this? I think model/view
programming is so integral to Qt 4 programming it should warrant some
extra attention in a Python layer.

Arve

On 7/18/06, Phil Thompson <phil at riverbankcomputing.co.uk> wrote:
> On Monday 17 July 2006 10:09 pm, Arve Knudsen wrote:
> > On 7/17/06, Andreas Pakulat <apaku at gmx.de> wrote:
> > > On 17.07.06 22:00:41, Arve Knudsen wrote:
> > > > Ok, I found the original thread. There is no explanation as to why no
> > > > extra reference is kept however.
> > >
> > > I don't know too much about python refcounting, but I think one problem
> > > could be what to do if the model index disappears. Also decrease the
> > > reference count? This could lead to a problem if "something" else still
> > > needs the object... Phil needs to answer this.
> >
> > When the model index is destroyed, it should decrease the reference
> > count seems like the obvious answer. If the object is referred to
> > elsewhere its reference count should reflect this.
>
> And you also have to implement the hooks for the cyclic garbage collector.
>
> > > > There might be a good reason for this
> > > > behaviour, but it does represent a rather nasty pitfall.
> > >
> > > Well, that's probably a reason why it was introduced so late, you had to
> > > use internalId before.
> >
> > My impression from reading the thread is that it was non-trivial to
> > implement, but added out of a real need, expressed by users.
>
> It was trivial to implement, once it was pointed out to me that the original
> (automated) wrapping was useless given the way it is supposed to be used.
>
> There are plenty of other places where you have to keep an external reference
> to stop an object being garbage collected causing a crash. I just need to
> decide if this is worth making a special case.
>
> Phil
>
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