Swig wrapping C++ Polymorphism

[James Carroll]

Hi, I asked this on the SWIG mailing list, but it's pretty dead over there....
I'm trying to get Python to pass a subclass of a C++ object to another
C++ object...

I have three C++ classes,

TiledImageSourc e

ZoomifyReaderWx which ISA TiledImageSourc e

TiffWriter which has a method which takes a TiledImageSourc e

reader = bright.ZoomifyR eaderWx()
writer = bright.TiledTif fWriter()
writer.SetImage Source(reader) <- doesn't work, error below.

TiffWriter has a SetImageSource method that takes a pointer to a
TiledImageSourc e.
When I try to pass an instance of ZoomifyReaderWx to TiffWriter, SWIG
can't hook the two up.

How can I fix this? I think I need a typemap, but I'm not sure of the syntax.

Thanks!
-Jim
Test script
----------------------------

reader = bright.ZoomifyR eaderWx()
reader.Open("C:/Slides/test.pff")

writer = bright.TiledTif fWriter()
writer.SetImage Source(reader)
writer.CreateFi le("C:/Slides/test.tif")

while not writer.IsFinish ed():
writer.ProcessA Bit()
print ".",

Exception
----------------------------
C:\jimc\prj\bri ght\scripts\vsE dit>python piplineTest.py
Traceback (most recent call last):
File "piplineTest.py ", line 11, in ?
writer.SetImage Source(reader)
File "C:\jimc\prj\br ight\scripts\vs Edit\bright.py" , line 88, in SetImageSource

def SetImageSource( *args): return _bright.TiledTi ffWriter_SetIma geSource(*ar
gs)
TypeError: argument number 2: a 'TiledImageSour ce *' is expected, 'PySwigObject(
_p_ZoomifyReade rWx)' is received
Interface files (exceprts)
----------------------------

class ZoomifyReaderWx : public TiledImageSourc e
{
public:
bool Open(wxString filename);
void Close();

ZoomifyReaderWx ();
//%pragma(python) addtomethod = "__init__:self. _setOORInfo(sel f)"

// necessary for ZoomableImageRe ader
virtual int GetWidth(int reduction = 0);
virtual int GetHeight(int reduction = 0);
....
class TiledTiffWriter
{
public:
TiledTiffWriter ();
//%pragma(python) addtomethod = "__init__:self. _setOORInfo(sel f)"

void SetImageSource( TiledImageSourc e *source);
void SetJpegQuality( int quality) { m_iJpegQuality = quality; }
void CreateFile(char *filename);
....

class TiledImageSourc e
{
public:
//%pragma(python) addtomethod = "__init__:self. _setOORInfo(sel f)"

virtual int GetWidth(int reduction = 0);
virtual int GetHeight(int reduction = 0);