Subclassing: CallWindowProc using a method?

[Chris Holbrook]

Can I CallWindowProc using a method rather than a function, to subclass a window?

Compiler doesn't like the "dot" here (error 526 Period not allowed):

GrOldProc = SetWindowLong(hGW, %GWL_WNDPROC, codeptr(me.MethodGrProc)) ' Subclasses Graphic control

[Bob Zale]

No. A METHOD is not a function. Different conventions.

[Chris Holbrook]

Thanks Bob.

[Edwin Knoppert]

Something like?..

fptr = @pUnk[offset]

[Chris Holbrook]

Edwin, I thought about it but as it happens I have a global array of the class in question so I can just send a message to the subclass function with the index of the class member.

[Michael Mattias]

Call me simple, but why not just have the subclass proc call (right word?) the method?

[Chris Holbrook]

Call me simple, but why not just have the subclass proc call (right word?) the method?

as there are lots of class members in the array, it has to know which one to call.

[Michael Mattias]

as there are lots of class members in the array, it has to know which one to call

??

You know the message, and SetWindowLong(hWnd, GWL_USERDATA) can hold all kinds of info re the 'state' of the program and/or main window.

FUNCTION SubClassProc ( hWnd, uMSG...) 

     CASE message_of_interest 
          My_data =  GetWindowLong (getParent(hWnd), GWL_USERDATA) 
          SELECT CASE My_data
             case  1 
                 Z = object.method_one
             case  2 
                 Z = object.method_two

...
        FUNCTION= CallWindowProc (dwOldProc, hWnd...........

???

[Chris Holbrook]

???

more like:

function WndProc(byval hWnd as dword, byval wMsg as dword, byval wParam as dword, byval lParam as long) as long
    ....
  static wlx as long
    ....
  select case wMsg
    case 0 ' special case - the winlet is sending its id
              ' or -1 if it is no longer selected
        if hWnd = 0 then
            select case wparam
                case 0
                    wlx = lparam
                case -1
                    wlx = -1
            end select
        end if
        exit function ' do NOT pass the event on to the classproc
    '
    case someothermessage
        if wlx > -1 then gWL(wlx).someothermethod
    ....

Added: Forgot to say that I'm just calling the function with the first two arguments set to zero. If you prefer, you can use a WM_USER + offset message instead.

[Michael Mattias]

Um, so what is the problem?

Calll me overly optimistic, but it sure looks like you have everything managed in the subclass procedure.

[Chris Holbrook]

Um, so what is the problem?

The problem was resolved by post #2, q.v. Since then it's just been polite conversation...