invoking CallWindowProc

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zhak

Joined: 12 Apr 2005
Posts: 501
Location: Belarus

zhak 28 Apr 2006, 07:21

Hi, people. Yesterday I was fighting Windows heroically for almost 5 hours trying to set button text font and color... I won at last, but still confused. Here's my question:
Microsoft gives an example for subclass procedure:

Code:

// Subclass procedure 
LRESULT APIENTRY EditSubclassProc(
    HWND hwnd, 
    UINT uMsg, 
    WPARAM wParam, 
    LPARAM lParam) 
{ 
    if (uMsg == WM_GETDLGCODE) 
        return DLGC_WANTALLKEYS; 
 
    return CallWindowProc(wpOrigEditProc, hwnd, uMsg, 
        wParam, lParam); 
}

So, as I understand, wndproc has to return smth. if a message is processed or invoke CallWindowProc if a message is not processed (as stated in SDK)
For example:

Code:

proc ButtonSubclassProc, hWnd, uMsg, wParam, lParam
    mov eax, [uMsg]
    cmp eax, WM_PAINT
    jz .paint
    invoke CallWindowProc, <params>
    ret
  .paint:
    <message processing routine>
    xor eax, eax
    ret

But this makes my app crazy. It consumes 90% of CPU, it redraws the entire dialog, it doesn't work. The solution is simple: invoke CallWindowProc in the beginning, and then process messages (if any).

Code:

proc ButtonSubclassProc, hWnd, uMsg, wParam, lParam
    invoke CallWindowProc, <params>
    mov eax, [uMsg]
    cmp eax, WM_PAINT
    jz .paint
  .ret:
    xor eax, eax
    ret
  .paint:
    <message processing routine>
    jmp .ret

WHY IS IT SO??? Why should I invoke CallWindowProc and then process messages if Microsoft says to process messages, and invoke CallWindowProc for messages that are not processed???

28 Apr 2006, 07:21

Kermil

Joined: 26 Oct 2005
Posts: 35
Location: Russia

Kermil 28 Apr 2006, 08:51

I see only one reason of such behaviour, you transfer wrong parameter to CallWindowProc. You should transfer to CallWindowProc correct address of old window procedure. But I can be mistaken. Show your code completely.

28 Apr 2006, 08:51

zhak

Joined: 12 Apr 2005
Posts: 501
Location: Belarus

zhak 29 Apr 2006, 10:29

here is the complete template:

Description:		Download
Filename:	btn.zip
Filesize:	1.83 KB
Downloaded:	300 Time(s)

29 Apr 2006, 10:29

Kermil

Joined: 26 Oct 2005
Posts: 35
Location: Russia

Kermil 02 May 2006, 07:54

I have looked your code and changed it, look below:

Code:

proc NumPadButtonsProc, hWnd, uMsg, wParam, lParam
    mov esi, [globals]
    mov eax, [uMsg]
    cmp eax, WM_PAINT
    jz .paint
    cmp eax, WM_LBUTTONDOWN
    jz .paint
    cmp eax, WM_LBUTTONDBLCLK
    jz .paint
    cmp eax, WM_LBUTTONUP
    jz .paint
    cmp eax, WM_MOUSEMOVE
    jz .paint
    cmp eax, WM_NCMOUSEMOVE
    jz .paint
    lea eax, [esi+global.lpDefNumPadButtonsProc]
    invoke CallWindowProc, [eax], [hWnd], [uMsg], [wParam], [lParam] ; not handled messages
    ret
.ret:
    mov eax, 1
    ret
.paint:
    lea eax, [esi+global.lpDefNumPadButtonsProc]
    invoke CallWindowProc, [eax], [hWnd], [uMsg], [wParam], [lParam] ; this call needed for drawing the button
    xor ecx, ecx
    mov edx, [hWnd]
    lea esi, [esi+global.hDlgMain_bn0]
  @@:
    lodsd
    cmp eax, edx
    jz .numpad
    inc ecx
    cmp ecx, (BN_SIGN-BN_0)
    jnz @b
    lodsd
    cmp eax, edx
    jnz .ret
  .numpad:
    shl ecx, 1
    lea esi, [ecx+szDlgMain_bn0Caption]
    push 00FF0000h      ;blue color
    push esi
    push eax
    call setButtonTextAndColor
    xor eax, eax
    ret
endp

02 May 2006, 07:54

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