Keyboard subclassing using DDT

[Scott Turchin]

I created a textbox, told it to call KeyboardCallback.

Life is good, I can type in the box, must be working...

I need to scan what is being typed in there however.

I'm trying to keep ZERO global variables right now unless they are essential.

Since DDT works and I don't need globals to operate a dialog (thanks Lance and everyone, finally learning!)...


I wrote this, and it DID work as a subclass routine the old fashioned way, but I took that part out..

I'm tired and it's after midnight, so maybe I just didn't see somethign I should have...


It does not return however....Am I not checking the right parameter? It DID work as a subclass...

CallBack Function KeyboardCallBack() As Long
Local St      As String
Select Case CbMsg
    Case %WM_KEYUP
         Control Get Text CbHndl, %IDTEXT2 To St
         If St = "PASSWORD" Then Control Enable CbHndl,%IDBUTTON2
End Select
End Function

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Scott
mailto:[email protected][email protected]</A>

[Lance Edmonds]

take a look at


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lance
powerbasic support
mailto:[email protected][email protected]</a>

[Scott Turchin]

Hmmmm That's what I had, with one exception:


GetParent(hWnd&)


Thanks!

Scott


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Scott
mailto:[email protected][email protected]t</A>

[Mike Doty]

'Lance, saw your subclassing posting
'How/where is the value of the key pressed obtained?
'Example: User pressed "A" or "a" or "1" so get a
'record, etc and continue processing.
'
'It would be really great to be able to float a
'dialog around the screen go get input at any location.
'This would allow drawing a graphical system then just
'putting an input control on it.
'
'To go even a little future, a picture of a keyboard
'could be shown on the screen so the user could click
'instead of type.
'Thanks, Mike
'

#COMPILE EXE
#INCLUDE "WIN32API.INC"

GLOBAL gOldSubClassProc&

CALLBACK FUNCTION AnyButton
    DIALOG END CBHNDL, ABS(CBCTL = %IDOK)
END FUNCTION

CALLBACK FUNCTION EditCallback
    ' This is the callback function.
    ' We can't intercept keyboard messages like this, we need to subclass...
    IF CBMSG = %WM_KEYUP THEN MSGBOX "TADA"
END FUNCTION

CALLBACK FUNCTION DlgCallBack
    LOCAL hEdit&
    SELECT CASE CBMSG
        CASE %WM_INITDIALOG
            ' Subclass the edit control
            CONTROL HANDLE CBHNDL, 102 TO hEdit&
            gOldSubClassProc = SetWindowLong(hEdit&, %GWL_WNDPROC, CODEPTR(SubClassProc))
        CASE %WM_DESTROY
            ' Important! Remove the subclassing
            SetWindowLong hEdit&, %GWL_WNDPROC, gOldSubClassProc
    END SELECT
END FUNCTION

FUNCTION PBMAIN
    #REGISTER NONE
    REGISTER hDlg&
    LOCAL Result&

    DIALOG NEW 0, "Subclassed EDIT control with DDT Example",,, 240, 180, %DS_CENTER OR %WS_SYSMENU _
        OR %DS_CONTEXTHELP OR %WS_THICKFRAME OR %WS_CLIPSIBLINGS OR %WS_CLIPCHILDREN, TO hDlg

    CONTROL ADD BUTTON,   hDlg, %IDOK,     "&Ok",     190, 10, 40, 14 CALL AnyButton
    CONTROL ADD BUTTON,   hDlg, %IDCANCEL, "&Cancel", 190, 25, 40, 14 CALL AnyButton
    CONTROL ADD COMBOBOX, hDlg, 101,, 10, 10, 170, 100, %CBS_DROPDOWNLIST OR %WS_TABSTOP
    CONTROL ADD TEXTBOX,  hDlg, 102, "This is an edit control", 10, 30, 170, 130, %ES_MULTILINE _
        OR %ES_WANTRETURN OR %WS_BORDER OR %WS_HSCROLL OR %WS_VSCROLL OR %WS_TABSTOP, _
        %WS_EX_CLIENTEDGE CALL EditCallBack
    COMBOBOX ADD hDlg, 101, "This is a combo box!"
    COMBOBOX SELECT hDlg, 101, 1

    FOR x& = 1 TO 10
        a$ = a$ + $TAB + FORMAT$(RND(1) * 100000!, "$#######.##") + $CRLF
    NEXT x&
    CONTROL SET TEXT hDlg, 102, a$ + a$

    hFont& = GetStockObject(%SYSTEM_FIXED_FONT)
    CONTROL SEND hDlg, 102, %WM_SETFONT, hFont&, %TRUE
    DIALOG SHOW MODAL hDlg CALL DlgCallBack
    'Not executed until dialog finishes
END FUNCTION

FUNCTION SubClassProc(BYVAL hWnd&, BYVAL wMsg&, BYVAL wParam&, BYVAL lParam&) AS LONG
    ' Process our messages in this subclass procedure
    SELECT CASE wMsg&
        CASE %WM_KEYDOWN
            SetWindowText GetParent(hWnd&), "WM_KEYDOWN"
        CASE %WM_KEYUP
            SetWindowText GetParent(hWnd&), "WM_KEYUP"
        CASE %WM_CHAR
            SetWindowText GetParent(hWnd&), "WM_CHAR"
    END SELECT
    ' Pass the message on to the original window procedure... the DDT engine!
    FUNCTION = CallWindowProc(gOldSubClassProc, hWnd&, wMsg&, wParam&, lParam&)
END FUNCTION

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[Lance Edmonds]

The instance subclass callback function "SubclassProc()" intercepts the keystroke messages. You'll find the details of what wParam and lParam contain in the relevant sections of WIN32.HLP - see WM_KEYDOWN, WM_KEYUP, WM_CHAR, etc.

Subclassing is discussed in (wait for it!) the Petzold and Rector/Newcomer book's...

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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>