Step 3: Declare native classes and global functions

Step 3: Declare native classes and global functions

For each native class that the nonvisual extension supports, declare an ANSI C++ class that inherits from IPBX_NonVisualObject, which is the ancestor class for all nonvisual PowerBuilder native classes.

The declaration of the class can be placed in a header file, and it must include Invoke and Destroy methods. This is a simple prototype for a nonvisual class:

#include "pbext.h"
 
class CMyClass : public IPBX_NonVisualObject
{
enum MethodIDs
{
   mFunca = 0,
   mFuncb = 1
};
public:
   // constructor, destructor
   CMyClass()
   virtual ~CMyClass()

   // member methods
   PBXRESULT Invoke(
      IPB_Session   *session, 
      pbobject   obj, 
      pbmethodID   mid,
      PBCallInfo   *ci
   );
   void Destroy();
 
private:
   void funcA(IPB_Session* session, pbobject obj,
       PBCallInfo* ci);
   void funcB(IPB_Session* session, pbobject obj,
       PBCallInfo* ci);
};

If you declare global functions in your extension, the extension must export the PBX_InvokeGlobalFunction method. The following PBX_GetDescription call declares three global functions: bitAnd, bitOr, and bitXor:

PBXEXPORT LPCTSTR PBXCALL PBX_GetDescription()
{
   static const TCHAR desc[] = {
      "globalfunctions\n"
      "function int bitAnd(int a, int b)\n"
      "function int bitOr(int a, int b)\n"
      "function int bitXor(int a, int b)\n"
      "end globalfunctions\n"
   };
 
  return desc;
}