Re: Wrapping wxArtProvider class

I've made a lot of progress on my wrapping of wxArtProvider.  It is in
fact almost complete. However, there's one nagging problem regarding
the perl callbacks.

I'm having issues with wxSize objects getting double deleted somewhere
in the call to wxArtProvider::CreateBitmap.  As near as I can tell,
what happens is:
1) Perl code calls Wx::ArtProvider::GetBitmap.
2) XS code for Wx::ArtProvider::GetBitmap makes a wxSize object from
either the parameter passed, or from wxDefaultSize.
3) XS code calls down to wxArtProvider::GetBitmap
4) In the guts of here, a call is made out to
wxPlArtProvider::CreateBitmap, passing the wxSize object along
5) The XS for wxPlArtProvider::CreateBitmap creates a Wx::Size object
to pass on to the perl code
6) The perl code does its thing
7) The Wx::Size object created in #5 goes out of scope, and the
underlying wxSize object gets destroyed
8) Call frames finish and we end up back in the XS for
Wx::ArtProvider::GetBitmap
9) This code delets the same underlying wxSize object again
10) Reams of warnings from glibc about free()ing invalid pointers are
emitted as this chain of events repeats.

I can work around this by allocating a copy of the size on the heap in
the XS for Wx::ArtProvider::CreateBitmap and then letting / assuming
that it will be deleted by perl, but somehow this seems dirty.  But if
it's the right way to go, then I guess the attached patch is okay.

Attached is a patch against 0.22 with my progress so far.  Other than
the problem described here, it seems to work for all the static
functions of wxArtProvider, and for deriving your own provider from
Wx::PlArtProvider.  To demonstrate the latter, I added an artprov
sample based on the minimal sample from wxPerl and the artprov sample
from wxWidgets.

As an aside, the build process for my code, and for XS/PlWindow.xsp
leaves the .h files they generate in cpp/ even after a make realclean.
 What's the proper way to fix this?

-- 
    -- Cheetah

wx-artprov-4.patch.gz
Description: GNU Zip compressed data