ObjPtr

[Scott Slater]

I am looking for an easy way to access an object created in one sub from a call back function without making the object var global. I can use the ObjPtr to pass a pointer to the callback via the DIALOG SET/GET USER area, but once I am in the callback how to I reference the pointer that was returned by ObjPtr? What is the best (safest) way to manipulate the object within the callback?

[José Roca]

Call this function:

' ========================================================================================
' This function allows to make an object variable from a pointer.
' An alternative is to use POKE or MoveMemory, e.g.
' POKE DWORD, VARPTR(pUnk), pObj
' IF ISOBJECT pUnk THEN pUnk.AddRef
' ========================================================================================
FUNCTION Ptr2Obj (BYVAL pObj AS DWORD) AS IUnknown
   LOCAL pUnk AS IUnknown
   LOCAL pv AS DWORD PTR
   IF pObj = %NULL THEN EXIT FUNCTION
   pv = VARPTR(pUnk)
   @pv = pObj
   IF ISOBJECT(pUnk) THEN
      pUnk.AddRef
      FUNCTION = pUnk
   END IF
END FUNCTION
' ========================================================================================

[Michael Mattias]

Haven't tried but why not pass the OBJPTR "AS objecttype PTR" or retrieve it in your callback (code not shown)

Best guess..

FUNCTION myCallback (BYVAL hWnd AS LONG, other params ) 
  LOCAL pOBJ AS objectType PTR 

  DIALOG GET USER  hWnd, number to pOBJ 
  ...

END FUNCTION

Is that allowed?

[José Roca]

Is that allowed?

No.

[Edwin Knoppert]

Haven't tried but why not pass the OBJPTR "AS objecttype PTR" or retrieve it in your callback (code not shown)

Best guess..

FUNCTION myCallback (BYVAL hWnd AS LONG, other params ) 
  LOCAL pOBJ AS objectType PTR 

  DIALOG GET USER  hWnd, number to pOBJ 
  ...

END FUNCTION

Is that allowed?

http://www.powerbasic.com/support/pbforums/showthread.php?t=41159

[Michael Mattias]

>>Is that allowed?
> No

Oh, well, it was a thought.

I've always said if you don't ever have any bad ideas, you don't have enough ideas, period.

[Scott Slater]

Haven't tried but why not pass the OBJPTR "AS objecttype PTR"

I already tried this and it wouldn't allow it. It would however be a great new feature. Maybe time for a feature request.

[Scott Slater]

Call this function:

Thanks José