[Pyobjc-dev] Still struggling with NSOutlineView

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

I just noticed that my PythonBrowser application doesn't work correctly after
all if I don't subclass PythonItem from NSObject. I was getting strange messages
in the log if I tried to unpack certain items:

2003-01-15 21:48:37.838 python[13055] PythonItem instance has no
attribute '__getitem__'

but I was sure *I* didn't do any subscripting on PythonItem instances. It
appears Cocoa is calling it (*), through PyObjC, and while trying to find what's
wrong I came across this snippet in Modules/objc/objc_support.m:

        else if (PySequence_Check(argument))  
          *(id *) datum = [OC_PythonArray newWithPythonObject:argument];

PySequence_Check() is a lame check, it always returns true for simple instances.
But since there's a PyDict_Check() below (which really checks isinstance(x,
dict)), I think the following would be better/safer:

        else if (PyList_Check(argument) || PyTuple_Check(argument))  
          *(id *) datum = [OC_PythonArray newWithPythonObject:argument];

However, if I make that change, PythonBrowser doesn't run at all anymore: it
crashes before any window is shown.

So I'm pretty sure my Python objects are (wrongly) wrapped in an OC_PythonArray
object, yet when they are wrapped in a OC_PythonObject (which would happen after
my change) it stops working completely.

*) I have no clue why NSOutlineView would do that: perhaps it tries to get at
children by itself if the object is array-like, instead of going through
outlineView:child:ofItem: ? The NSOutlineView and NSOutlineViewDataSource
documentation don't seem to mention such magic.

Just