Announcement

**Pierre Bellisle** · 3 Feb 2008, 08:10 PM

One way is to use minus 255 to 0...

Code:

#COMPILE EXE '#win 8.04#
#DIM ALL
#INCLUDE "Win32Api.inc" '#2005-01-27#
#INCLUDE "CommCtrl.inc"
 
%IDC_Frame1     = 101
%IDC_Frame2     = 102
%IDC_VTrackbar1 = 201
%IDC_VTrackbar2 = 202
%IDC_Label1     = 301
%IDC_Label2     = 302
 
%DAC_MIN_1      = 0
%DAC_MAX_1      = 255
 
%DAC_MIN_2      = -255
%DAC_MAX_2      = 0
'______________________________________________________________________________
 
CALLBACK FUNCTION PbProc()
 
 SELECT CASE AS LONG CBMSG
 
   CASE %WM_INITDIALOG
     CONTROL SEND CBHNDL, %IDC_VTrackbar1, %TBM_SETRANGE, %TRUE, MAKDWD(%DAC_MIN_1, %DAC_MAX_1) 'Set range
     CONTROL SEND CBHNDL, %IDC_VTrackbar1, %TBM_SETTICFREQ, 8, 0   'Set tic frequency
     CONTROL SEND CBHNDL, %IDC_VTrackbar1, %TBM_SETPAGESIZE, 0, 10 'Set page size
 
     CONTROL SEND CBHNDL, %IDC_VTrackbar2, %TBM_SETRANGE, %TRUE, MAKLNG(%DAC_MIN_2, %DAC_MAX_2) 'Set range
     CONTROL SEND CBHNDL, %IDC_VTrackbar2, %TBM_SETTICFREQ, 8, 0   'Set tick frequency
     CONTROL SEND CBHNDL, %IDC_VTrackbar2, %TBM_SETPAGESIZE, 0, 10 'Set page size
     CONTROL SEND CBHNDL, %IDC_VTrackbar2, %TBM_SETPOS, %TRUE, %DAC_MIN_2 'Set initial position
 
   CASE %WM_VSCROLL
     'Handle in CBLPARAM, code in LO(WORD, CBWPARAM), position in HI(INTEGER, CBWPARAM)
     SELECT CASE LOWRD(CBWPARAM)
       CASE %TB_THUMBTRACK, %TB_LINEDOWN, %TB_LINEUP, _
            %TB_PAGEDOWN, %TB_PAGEUP, %TB_TOP, %TB_BOTTOM
 
         SELECT CASE GetDlgCtrlID(CBLPARAM) 'Handle in CBLPARAM to id
 
           CASE %IDC_VTrackbar1
             CONTROL SET TEXT CBHNDL, %IDC_Label1, STR$(HI(INTEGER, CBWPARAM)) 'Update label with position
 
           CASE %IDC_VTrackbar2
             CONTROL SET TEXT CBHNDL, %IDC_Label2, STR$(ABS(HI(INTEGER, CBWPARAM))) 'Update label with position
 
         END SELECT
     END SELECT
 
 END SELECT
 
END FUNCTION
'______________________________________________________________________________
 
FUNCTION PBMAIN()
 LOCAL hDlg AS DWORD
 
 DIALOG NEW %HWND_DESKTOP, "Trackbar 0 to 255 and 255 to 0", , , 265, 210, _
            %WS_CAPTION OR %WS_MINIMIZEBOX OR %WS_SYSMENU, 0 TO hDlg
 
 CONTROL ADD FRAME, hDlg, %IDC_Frame1, "DA1", 95, 2, 31, 198
 CONTROL ADD "MsCtls_TrackBar32", hDlg, %IDC_VTrackbar1, "", 98, 15, 25, 170, _
             %WS_CHILD OR %WS_VISIBLE OR %WS_TABSTOP OR %TBS_VERT OR %TBS_LEFT OR %TBS_AUTOTICKS
 CONTROL ADD LABEL, hDlg, %IDC_Label1, " 0", 100, 188, 20, 8, _
             %WS_CHILD OR %WS_VISIBLE OR %SS_CENTER, %WS_EX_LEFT OR %WS_EX_LTRREADING
 
 CONTROL ADD FRAME, hDlg, %IDC_Frame2, "DA2", 160, 2, 31, 198
 CONTROL ADD "MsCtls_TrackBar32", hDlg, %IDC_VTrackbar2, "", 163, 15, 25, 170, _
             %WS_CHILD OR %WS_VISIBLE OR %WS_TABSTOP OR %TBS_VERT OR %TBS_LEFT OR %TBS_AUTOTICKS
 CONTROL ADD LABEL, hDlg, %IDC_Label2, " 0", 166, 188, 20, 8, _
             %WS_CHILD OR %WS_VISIBLE OR %SS_CENTER, %WS_EX_LEFT OR %WS_EX_LTRREADING
 
 DIALOG SHOW MODAL hDlg, CALL PbProc
 
END FUNCTION
'______________________________________________________________________________
'

**Jules Marchildon** · 3 Feb 2008, 08:24 PM

Hi Pierre,

Thanks for the response, I decided to go that way, but I thought that in the back of my
mind, you could create the control in that orientation, but guess not.

Thx.
Regards,
Jules

**Michael Mattias** · 4 Feb 2008, 08:51 AM

Maybe, maybe not?

TBS_REVERSED
Version 5.80.This style bit is used for "reversed" trackbars, where a smaller number indicates "higher" and a larger number indicates "lower." It has no effect on the control; it is simply a label that can be checked to determine whether a trackbar is normal or reversed.

But converting positions on WM_NOTIFY/TBN_ENDDRAG from 0:255 to 255:0 can't be all that hard, can it?

**Walt Thompson** · 4 Nov 2008, 06:56 PM

Hi Jules;

This may do it for you.

Code:

#COMPILE EXE
#DIM ALL

'---Includes...
#INCLUDE "WIN32API.INC"
#INCLUDE "COMMCTRL.INC"
#INCLUDE "PBForms.INC"

'---Constants...
%IDD_Form1           =  101  'main form

%IDC_VTrackbar1      = 1601
%IDC_Label3          = 1602
%IDC_VTrackbar2      = 1603
%IDC_Label4          = 1604

%IDC_Frame2          = 1801
%IDC_Frame3          = 1802

%DAC_MAX             = 255
%DAC_MIN             = 0

'---Delcares...
DECLARE CALLBACK FUNCTION ShowForm1Proc()
DECLARE FUNCTION ShowForm1(BYVAL hParent AS DWORD) AS LONG

'------------------------------------------------------------------------------
'
'------------------------------------------------------------------------------
SUB UpdateAnalogOutputStatus(BYVAL hDlg AS DWORD, BYVAL dac1 AS BYTE, BYVAL dac2 AS BYTE)

    '-update the position of the  trackbars
    ' not necessary like scrollbars, but caller can set it manually with this call.
    'CONTROL SEND hDlg,%IDC_VTrackbar1,%TBM_SETPOS,%TRUE, (255 - dac1)
    CONTROL SEND hDlg,%IDC_VTrackbar2,%TBM_SETPOS,%TRUE, dac2

    '-update the values
    CONTROL SET TEXT hDlg,%IDC_Label3, STR$(dac1)
    CONTROL SET TEXT hDlg,%IDC_Label4, STR$(dac2)

END SUB

'------------------------------------------------------------------------------
'
'------------------------------------------------------------------------------
FUNCTION PBMAIN()
    PBFormsInitComCtls( %ICC_WIN95_CLASSES OR %ICC_DATE_CLASSES OR %ICC_INTERNET_CLASSES ) 'Macro
    CALL ShowForm1(%HWND_DESKTOP)
END FUNCTION

'------------------------------------------------------------------------------
'
'------------------------------------------------------------------------------
CALLBACK FUNCTION ShowForm1Proc()
    LOCAL lrt AS LONG
    LOCAL cstatus AS STRING
    STATIC cardAddress AS LONG
    LOCAL tPos1 AS LONG, tPos2 AS LONG
    '---
    SELECT CASE AS LONG CBMSG
        '---
        CASE %WM_INITDIALOG
            '-initialize trackbars...
            CONTROL SEND CBHNDL,%IDC_VTrackbar1,%TBM_SETRANGE,-1,MAKDWD(00,255) 'set range
            CONTROL SEND CBHNDL,%IDC_VTrackbar1,%TBM_SETPOS, -1, 255
            CONTROL SEND CBHNDL,%IDC_VTrackbar1,%TBM_SETTICFREQ,8,0   'set tic frequency
            CONTROL SEND CBHNDL,%IDC_VTrackbar1,%TBM_SETPAGESIZE,0,10 'set page size

            CONTROL SEND CBHNDL,%IDC_VTrackbar2,%TBM_SETRANGE,%TRUE,MAKDWD(0,255) 'set range
            CONTROL SEND CBHNDL,%IDC_VTrackbar2,%TBM_SETTICFREQ,8,0   'set tick frequency
            CONTROL SEND CBHNDL,%IDC_VTrackbar2,%TBM_SETPAGESIZE,0,10 'set page size
            CALL UpdateAnalogOutputStatus(CBHNDL,%DAC_MIN,%DAC_MIN)   'set thumb pos to min
        '---
        CASE %WM_NCACTIVATE
            STATIC hWndSaveFocus AS DWORD
            IF ISFALSE CBWPARAM THEN
                hWndSaveFocus = GetFocus()
            ELSEIF hWndSaveFocus THEN
                SetFocus(hWndSaveFocus)
                hWndSaveFocus = 0
            END IF
        '---
        CASE %WM_COMMAND
            SELECT CASE AS LONG CBCTL
            END SELECT
        '---
        CASE %WM_VSCROLL '-handle both trackbars...
            SELECT CASE LOWRD(CBWPARAM)
                CASE %TB_THUMBTRACK, _   '-Mouse
                     %TB_LINEDOWN,   _   '-Keyboard
                     %TB_LINEUP,     _   '-Keyboard
                     %TB_PAGEDOWN,   _   '-Keyboard
                     %TB_PAGEUP,     _   '-Keyboard
                     %TB_TOP,        _   '-Keyboard
                     %TB_BOTTOM          '-Keyboard
                    CONTROL SEND CBHNDL,%IDC_VTrackbar1,%TBM_GETPOS,0,0 TO tPos1
                    CONTROL SEND CBHNDL,%IDC_VTrackbar2,%TBM_GETPOS,0,0 TO tPos2
                    tPos1 = LOWRD(255 - tPos1)
                    tPos2 = LOWRD(tPos2)
                    CALL UpdateAnalogOutputStatus(CBHNDL,tPos1,tPos2)
            END SELECT
        '---
        CASE %WM_DESTROY
        '---
        CASE %WM_CLOSE
    END SELECT
END FUNCTION

'------------------------------------------------------------------------------
'
'------------------------------------------------------------------------------
FUNCTION ShowForm1(BYVAL hParent AS DWORD) AS LONG

    LOCAL lRslt  AS LONG
    LOCAL hDlg   AS DWORD
    LOCAL hFont1 AS DWORD

    DIALOG NEW hParent, "trackbar behavior, temp...", 131, 82, 406, 211, %WS_POPUP OR _
        %WS_VISIBLE OR %WS_CLIPSIBLINGS OR %WS_BORDER OR %WS_DLGFRAME OR %DS_3DLOOK OR %DS_NOFAILCREATE _
        OR %DS_SETFONT OR %WS_SYSMENU OR %WS_THICKFRAME, %WS_EX_LEFT OR %WS_EX_LTRREADING _
        OR %WS_EX_RIGHTSCROLLBAR OR %WS_EX_CONTROLPARENT OR %WS_EX_APPWINDOW, TO hDlg

    CONTROL ADD FRAME, hDlg, %IDC_Frame2,   "DA1", 91, 2, 31, 198
    CONTROL ADD LABEL, hDlg, %IDC_Label3,   " 0",96,188,20,8,%WS_CHILD _
                OR %WS_VISIBLE OR %SS_CENTER, %WS_EX_LEFT OR %WS_EX_LTRREADING

    CONTROL ADD "msctls_trackbar32", hDlg, %IDC_VTrackbar1,"",94,15,25,170,%WS_CHILD _
                OR %WS_VISIBLE OR %WS_TABSTOP OR %TBS_VERT OR %TBS_LEFT OR %TBS_AUTOTICKS

    CONTROL ADD FRAME, hDlg, %IDC_Frame3,   "DA2", 126, 2, 31, 198
    CONTROL ADD LABEL, hDlg, %IDC_Label4,   " 0", 132, 188, 20,8,%WS_CHILD _
                OR %WS_VISIBLE OR %SS_CENTER, %WS_EX_LEFT OR %WS_EX_LTRREADING
    CONTROL ADD "msctls_trackbar32", hDlg, %IDC_VTrackbar2,"",129,15,25,170,%WS_CHILD _
                OR %WS_VISIBLE OR %WS_TABSTOP OR %TBS_VERT OR %TBS_LEFT OR %TBS_AUTOTICKS

    hFont1 = PBFormsMakeFont("MS Sans Serif",8,700,%FALSE,%FALSE,%FALSE,%ANSI_CHARSET)


    CONTROL SEND hDlg, %IDC_Label3, %WM_SETFONT, hFont1, 0
    CONTROL SEND hDlg, %IDC_Label4, %WM_SETFONT, hFont1, 0

    DIALOG SHOW MODAL hDlg, CALL ShowForm1Proc TO lRslt

    CALL DeleteObject(hFont1)

    FUNCTION = lRslt
END FUNCTION

Announcement

Trackbar zero to 255 bottoms up

Trackbar zero to 255 bottoms up

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