Re: [Pyobjc-dev] Still struggling with NSOutlineView

[Just v. R. <ju...@le...>]

Ronald Oussoren wrote:

> > Ah, nice, thanks. That may have been a problem, but it did work for
> > me before, as long as PythonItem was subclassed from NSObject. The
> > main issue is that it doesn't work when it _isn't_ subclassed from
> > NSObject: it crashes as soon as you click (hm, I seem to recall it
> > didn't crash before your patch, maybe other PyObjC changes play a
> > role...).
> 
> It crashes when PythonItem is not subclasses from NSObject because
> NSOutlineView stashes away the result of outlineView_child_ofItem_
> *without increasing its reference count*. Later on it uses this
> pointer. If PythonItem is not subclassed from NSObject the values
> seem by outlineView:child:ofItem: (e.g. the Objective-C
> implementation) is an autoreleased proxy object (instance of
> OC_PythonObject). The PythonItem instance does not contain a
> reference to this proxy and therefore this will be autoreleased on
> the next loop through the eventloop. If the outlineview tries to use
> the proxy object later on your application goes boom.

Ah, now that clears the whole thing up! Thanks much. Makes sense if you
understand what happens. That's a keeper for the PyObjC phrase book,
once we have one...

> > Erm, where do you see a __doc__ item that's expandable? __doc__ is
> > usually a stirng or None, neither of which should be expandable...
> 
> If I start the PythonBrowser.app the window is filled with a the
> globals of the module, one of these is the __doc__ (which of type
> NoneType and has value None). On my system it is shown as an
> expandable item, but it is not in fact expandable.
> 
> The problem is larger than that: class AutoBaseClass is not
> expandable, while NiceError is. This doesn't seem to be a problem
> with the script: I've added some print-statements and those print the
> expected results. This might indicate a problem with the bridge.

Hm, strange. Let me know if it turns out to be a bug in my program after
all...

Just