Context sensitive help?

[Bern Ertl]

I'm trying to enable context sensitive help in a dialog with DDT. I've created the dialog using :

DIALOG NEW 0, Title$, ,, 300, 200, %DS_CONTEXTHELP OR %WS_CAPTION OR %WS_SYSMENU TO hDlg&

CONTROL ADD BUTTON, hDlg&, %IDSAVE, "Save / &Exit", _
150, 170, 60, 14, _
%BS_NOTIFY OR %BS_CENTER OR %BS_VCENTER OR %WS_TABSTOP CALL SaveButton

The dialog displays the ? box and the user can click on it and carry the arrow w/? mouse pointer to the Save button, but my callback function SaveButton is not receiving any messages (I was expecting %WM_HELP) when the user clicks on button. What have I done wrong (or am I missing)?

Bernard Ertl

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[Borje Hagsten]

The message is probably sent to the dialog's callback function.
If you use SetWindowContextHelpId(..) to set appropriate id for
control vs help file section, right after control has been
created, you can trap this id in dialog's %WM_HELP and show
proper help file popup. Simple sample:

'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
' Simple help context sample
'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
#COMPILE EXE
#INCLUDE "WIN32API.INC"
 
'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
' Main callback
'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
CALLBACK FUNCTION DlgProc() AS LONG
  SELECT CASE CBMSG
     CASE %WM_COMMAND
       IF CBCTL = 1 THEN DIALOG END CBHNDL, 1 '<- exit
 
     CASE %WM_HELP
        LOCAL hi AS HELPINFO PTR
        hi = CBLPARAM
        MSGBOX STR$(@hi.dwContextId) 'return 5, as set
 
  END SELECT
END FUNCTION
 
'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
' Create dialog and controls, etc
'¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
FUNCTION PBMAIN () AS LONG
  LOCAL hDlg AS LONG
 
  DIALOG NEW 0, "Help Context test ",,, 150, 50, %WS_SYSMENU OR %DS_CONTEXTHELP, 0 TO hDlg
  CONTROL ADD BUTTON, hDlg, 1,  "E&xit", 50, 10, 50, 14, 1
 
  CALL SetWindowContextHelpId(GetDlgItem(hDlg, 1), 5) 'set id to 5, just for test
 
  DIALOG SHOW MODAL hDlg CALL DlgProc
 
END FUNCTION

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[Semen Matusovski]

DDT doesn't give access to original callback.
Unlike WM_HELP really occurs in real callback for button (see a sample), in SaveButton you will not receive it.

   #Compile Exe
   #Dim All
   #Register None
   #Include "WIN32API.INC"
   
   Global gOldProc As Long
   
   CallBack Function SubClassProc
      Select Case CbMsg
         Case %WM_HELP
            Dim lphi As HELPINFO Ptr
            lphi = CbLparam
            MsgBox "Id = " & Str$(@lphi.iCtrlId), , "WM_HELP from SubClassProc"
            Function = 1: Exit Function
      End Select
      Function = CallWindowProc(gOldProc, CbHndl, CbMsg, CbWparam, CbLparam)
   End Function
   
   CallBack Function DlgProc
      Select Case CbMsg
         Case %WM_HELP
            Dim lphi As HELPINFO Ptr
            lphi = CbLparam
            MsgBox "Id = " & Str$(@lphi.iCtrlId), , "WM_HELP from DlgProc"
            Function = 1: Exit Function
      End Select
   End Function
   
   Function PbMain
       Local hDlg As Long
       Dialog New 0, "Context Help",,, 240, 180, %WS_CAPTION Or %WS_SYSMENU Or %DS_CONTEXTHELP, To hDlg
       Control Add Button,   hDlg, %IDOK,     "&Ok",     190, 10, 40, 14
       gOldProc = SetWindowLong (GetDlgItem(hDlg, %IDOK), %GWL_WNDPROC, CodePtr(SubClassProc))
       Control Add TextBox,  hDlg, 102, "", 10, 30, 170, 130, _
           %ES_MULTILINE Or %ES_WANTRETURN Or %WS_TABSTOP, %WS_EX_CLIENTEDGE
       Dialog Show Modal hDlg Call DlgProc
   End Function

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E-MAIL: [email protected]

[Bern Ertl]

Well, I'm calling the dialog with:

DIALOG SHOW MODELESS hDlg&

and :

DO
DIALOG DOEVENTS

'more code...

CONTROL GET CHECK hDlg&, %IDEXITBOX TO Dummy1&
'%IDEXITBOX is invisible & set by other buttons
LOOP UNTIL Dummy1&

So, I don't have a callback function for the dialog.

The PB DOCs say that the %DS_CONTEXTHELP for the dialog sends the %WM_HELP to the control which the user clicks on. But my control is not receiving one...

If I creat a callback for the dialog and it is receiving the %WM_HELP messages, how would I know which control was clicked?

'**************************
If you use SetWindowContextHelpId(..) to set appropriate id for
control vs help file section, right after control has been
created, you can trap this id in dialog's %WM_HELP and show
proper help file popup. Simple sample:
'**************************

I'm not sure (yet) what you mean by control vs. help file section. I was attempting to capture the %WM_HELP message in control's callback and then display a simple MSGBOX message. Are you saying there is an easy way to interface with a windows .HLP file?

Bernard Ertl

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[Bern Ertl]

Semen, I tried your example and it works nice. Thanks.

I'll be studying it now to figure out how it works.


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Bernard Ertl