Dialog Subclassing in 64 bit applications

[dannycat]

The following code is included in a dialog subclassing module I have used successfully in the 32-bit configuration of the application:

integer(HANDLE) :: hTabDlgProc(7)

!DEC$ IF DEFINED (WIN64)

hTabDlgProc(2) = SetWindowLongPtr(gdlg_tab2%hWnd, DWL_DLGPROC, LOC(Tab2DlgProc))

!DEC$ ELSE

hTabDlgProc(2) = SetWindowLong(gdlg_tab2%hWnd, DWL_DLGPROC, LOC(Tab2DlgProc))

!DEC$ ENDIF

The function referred to in the LOC() functionis defined as follows:

function Tab2DlgProc(hDlg, message, wParam, lParam)

!DEC$ ATTRIBUTES STDCALL :: Tab2DlgProc

use dfwin

implicit none

! Arguments

integer(SINT) :: Tab2DlgProc ! Declare the function

integer(HANDLE) :: hDlg ! Integer identifying the window handle of the dialog box

integer(UINT) :: message ! Integer identifying the window message

integer(fWPARAM) :: wParam ! message-specific information

integer(fLPARAM) :: lParam ! message-specific information

The SetWindowLong function returns a value in 32-bit version but returns zero in the64-bit versionwhere SetWindowLongPtr is required. Any ideas why this is? I suspect the function declaration:

integer(SINT) :: Tab2DlgPoc

If anyonecan help with this it will be most appreciated.

[IDZ_A_Intel]

I'm confused by your description. You should use SetWindowLongPtr in both architectures. The return type of the dialog procedure does not matter (or rather, (SINT) is correct.)

[dannycat]

Steve,

In my original code, writtenfor CVF, I utilisedSetWindowLong() and this worked fine. When I tried SetWndowLongPtr() the code would not compile. When I moved over to IVF and tried to compile the 64-bit config I got a message relating to the SetWindowLong() function having mis-matched arguments, supporting your statement above. I kept the original function in so that the code would still compile with CVF and as it also works OKfor 32-bit IVF. Unfortunately when I run the 64-bit config, the debugger shows a zero return from SetWindowLongPtr(), presumably indicating a problem.

What other reason would this function fail?

[IDZ_A_Intel]

Call GetLastError() after the fail to see why it failed.

[dannycat]

It comes up with error 1415 "Using PRIVATE dialog window words". Why should this be different for 64-bit when it works in 32-bit, unless the function is looking at the wrong words in dialog structure.

[Jugoslav_Dujic]

Hm. As far as I know, you aren't supposed to change the dialog procedure (the thingo returned by DWL_DLGPROC) in run-time. You can change the window procedure (the thingo returned by GWL_WNDPROC). Maybe Win32 lets you do that, but -- I think correctly -- Win64 won't.

Well, not sure how it worked in win32 in the first place -- maybe it would for some simple cases. From your subclassing procedure, do you CallWindowProc or return true/false?

For an explanation of differences between dialog procedure and window procedure, see this recent post of mine.

[dannycat]

[fortran]Jugoslav, I use CallWindowProc as shown below.[/fortran]

[fortran][/fortran]

[fortran]function Tab2DlgProc(hDlg, message, wParam, lParam)
!DEC$ ATTRIBUTES STDCALL :: Tab2DlgProc

use dfwin

implicit none

! Arguments
integer(SINT)    :: Tab2DlgProc  ! Declare the function
integer(HANDLE)  :: hDlg       ! Integer identifying the window handle of the dialog box
integer(UINT)    :: message    ! Integer identifying the window message
integer(fWPARAM) :: wParam     ! message-specific information
integer(fLPARAM) :: lParam     ! message-specific information

! Local Variables
integer(HANDLE)  :: hWndControl
integer(HANDLE)  :: hDCControl
integer(HANDLE)  :: ret, hbkcolor
integer          :: j

! delete any existing brush created earlier
if(hTabBackbrush(2).ne.0) then
  ret = DeleteObject(hTabBackbrush(2))
endif

select case (message)

! Dialog box drawing message - create  PURPLE background
case (WM_CTLCOLOREDIT,WM_CTLCOLORSTATIC)

! Edit Control
  hdcControl  = wparam
  hwndControl = lparam

! Use hwndControl to identify the control
  do j = 1 , nCtrl
    if(hWndControl.eq.hCtr(j).and.cTyp(j).eq.message) then
	  hTabBackbrush(2) = CreateSolidBrush(RGB(int1(cBkRGB(j,1)),int1(cBkRGB(j,2)),int1(cBkRGB(j,3))))    ! Create a brush
	  hbkcolor   = MSFWIN$SetBKColor(hdcControl,RGB(int1(cBkRGB(j,1)),int1(cBkRGB(j,2)),int1(cBkRGB(j,3))))    ! Set the text background 
	  Tab2DlgProc  = hTabBackbrush(2)    ! return the window background brush handle immediately	
	  return
	endif
  enddo

end select

! pass all other messages on to the default window procedure
Tab2DlgProc = CallWindowProc(hTabDlgProc(2), hDlg, message, wParam, lParam)

return

end function Tab2DlgProc
[/fortran]

[fortran]Are you suggesting an alternative method?[/fortran]

[anthonyrichards]

Not that it is relevant to your current discussion, but I think you should ensure that you pass on messages that you do not process inside the IF block and move the 'end select' and include a CASE DEFAULT to pas on all other messages, as follows

select case (message)

! Dialog box drawing message - create PURPLE background

case (WM_CTLCOLOREDIT,WM_CTLCOLORSTATIC)

Do...

if...

else

! If neither of these control messages are processed inside this if block,

! pass them on to the default window procedure

Tab2DlgProc = CallWindowProc(hTabDlgProc(2), hDlg, message, wParam, lParam)

end if...

end do

case default

! pass all other messages on to the default window procedure

Tab2DlgProc = CallWindowProc(hTabDlgProc(2), hDlg, message, wParam, lParam)

end select

return

end function

[dannycat]

Thanks Anthony, although it worked OK before I'll amend my code accordingly. As you said it doesn't solve my 64-bit problem though.

[Jugoslav_Dujic · Accepted solution]

Quoting anthonyrichards

Not that it is relevant to your current discussion, but I think you should ensure that you pass on messages that you do not process inside the IF block and move the 'end select' and include a CASE DEFAULT to pas on all other messages

No, his code structure is fine: there's a RETURN statement within CASE (WM_CTLCOLOR...), so it comes down to the same thing. Like you, Tony, I prefer the CASE DEFAULT, but he's fine as it is.

However, there are two other issues:

1) As I hinted above, try replacing DWL_DLGPROC with GWL_WNDPROC in the call to SetWindowLong(Ptr). I'm not sure how it ever worked in Win32, but it apparently does not in Win64.

2) You have a massive GDI leak -- every while you CreateSolidBrush, but never DeleteObject. Unfortunately, you need to go through some hoops to correctly create and delete the brushes, along the lines of:

[fortran]integer(HANDLE), save:: hPinkBrush = 0
....
case (WM_COLORSTATIC)
  !Create the brush only once, first time we enter here:
  if (hPinkBrush==0)
     hPinkBrush = CreateSolidBrush(...)
  ...
  Tab2DlgProc = hPinkBrush
case (WM_DESTROY)
  iret = DeleteObject(hBrush)
  iret = CallWindowProc(...)[/fortran]

I must say that the whole WM_CTLCOLOR* mechanism sucks, and it's probably a leftover from some GDI structure at Windows 3.1. They could have had WM_SETCOLOR (of which, IIRC, only PBM_SETCOLOR and another one exist), but we're apparently stuck with this...

[dannycat]

Juguslav,

Replacing DWL_DLGPROC with GWL_WNDPROC did the trick. With regard to the GDI memory leak I destroy the brush objects in the DLG_DESTROY segment of the dialog callback. The handles are stored globally within the module so that this can be done.

Thanks

Steve (dannycat)