Java HotSpot Virtual Machine

I am writing a c++ dll wrapper for a delphi dll so I can use JNI. It is all pretty messed up and I have everything working except for a few functions that take a delphi "procedure" pointer as an argument and then callback this procedure.

The Delphi documentation for the method in the dll is:


The relevant bits from my c++ header file are:

typedef int (CALLBACK* ToziMapDblClickON)(int *);
extern ToziMapDblClickON oziMapDblClickON;

The relevant bits from the cpp file are:

ToziMapDblClickON oziMapDblClickON;

void MapDblClickCallback(LPSTR oType,int x, int y, double Lat, double Lon,LPSTR UTMZone, double easting, double northing)
{
printf("Callbacktest");


}

JNIEXPORT jint JNICALL Java_oziphoto_nat_OZIJava_joziMapDblClickON
(JNIEnv * env, jclass jcla)
{
printf("start");
int i = oziMapDblClickON((int *)&MapDblClickCallback);
printf("end");
return i;
}

int LoadOziApiDll(void)
{
oziApiDll = LoadLibrary("oziapi.dll");
if (oziApiDll == NULL) {return -1;}
oziMapDblClickON = (ToziMapDblClickON)GetProcAddress(oziApiDll,"oziMapDblClickON");
if (!oziMapDblClickON) { FreeLibrary(oziApiDll);return -2;}
return 0;
}

When I call my function from Java my console prints "startCallbacktestend". Essentially the MapDblClickCallback function is being called as it is being passed to the oziMapDblClickON function in the delphi dll. When I double click in the program I am interfacing with I would expect the callback to be executed. It is not. I know that the program I am interfacing with has recieved the oziMapDblClickCallback request as it no longer processed the events in the normal way.

I think that there may be something wrong with the way I am passing the function pointer (if that is what it is) to the oziMapDblClickON function. Any ideas?