How to create a special masked edit control ?

[Hubert Brandel]

Hi,

i know that I can set a style for "only digit input", but I need this a little different. Allow digits, "+" or "-" (if I want), and the "," or "." ...

Is it possible to take over control of the keyboard behaviour of a edit control and how to do it ?

[Dave Biggs]

Various methods discussed in this thread.. http://www.powerbasic.com/support/pb...ad.php?t=39504

Especially see PB's Verify function.

[Hubert Brandel]

Thanks for the link, but I do need a TEXT control, that does not do anything if the wrong key is pressed. In PB 9.0 help I found:

control add textbox .... %ES_NUMBER, but the problem is, that this will not take +-,. as valid input. They write "subclassing a textbox that does ... rejecting unwanted keystrokes..." thats the point I need to get too.

I did this in other languages (wich is OOP), but did not find to do it in PowerBasic. Does this have somthing to do with the new objects ?

[Michael Mattias]

Yeah, I gotta write one of these today, too... I think.

What I want is something which looks like a combobox (dropdown style), which accepts only valid formatted dates , eg..

     [MM-DD-YYYY]

When the user presses <Enter> I want to check that this date is not already one of the items of the combobox.. and if not, add it and reset the control to accept another "date" .... but I also want to allow the user to select one of those items to bring it into the edit control so I can delete it.

I also wanted to incorporate a "date picker" or "calendar" control with this, but I have exactly zero space left on the screen. I was thinking maybe I'd just create date-picker control and put it over the edit box portion of the combobox when the user focuses on the combobox.

If I overlaid the date-picker control on top the CB's edit area then I would not need to worry about subclassing and mask-editing the combobox, although I'd still have to subclass the datepicker control to pick off the "Enter" key....

No, I did not design this originally... I'm matching the "familiar" behavior of an existing MRP system (Point.Man) for date entry.

Basically I think it's ugly, but in this case I think ugly is what I need to make prospects feel all warm and fuzzy about the software ... so they purchase it.

If anyone has done anything like this before I'd be interested in how you chose to do it.... since I obviously have not made up my own mind yet.


MCM

[Gösta H. Lovgren-2]

Hubert,

You will have to Subclass the control (Textbox) and in the SubClass test every key entered, then reject or use as you want. If you are unfamiliar with SubClassing, there's a very good starting example in the Samples folder on the PB disk.

=============================
"Wit is educated insolence."
Aristotle (384-322 B.C.)
=============================

[Chris Boss]

The best approach is to superclass the edit control.

Superclassing, is where you create a totally new class based on an existing window class.

Superclassing is better than subclassing when you need multiple instances of the control.

In the window procedure of the new control class, process the following messages and customize them:

WM_KEYUP
WM_KEYDOWN
WM_CHAR

[Michael Mattias]

Subclass procedure to allow only valid hex digits. The control uses style ES_UPPERCASE which should explain the way I handle some things.

FUNCTION DelimiterHexEditProc (BYVAL hWnd AS LONG, BYVAL wMSG AS LONG, BYVAL wPAram AS LONG, BYVAL lParam AS LONG) AS LONG

  STATIC dwProc AS DWORD, BeenHere AS LONG
  LOCAL szProp AS ASCIIZ * 64
  LOCAL  idCtrl AS LONG
  LOCAL  szText AS ASCIIZ * %MAX_PATH, lText AS LONG
  LOCAL  ichar  AS LONG


  IF ISFALSE beenHere THEN
      BeenHere = %TRUE
      szProp   = $PROP_OLD_WNDPROC
      dwProc   = getProp (hWnd, szProp)
  END IF

  SELECT CASE AS LONG wMSg

         CASE %WM_GETDLGCODE
             'FUNCTION =  %DLGC_WANTALLKEYS     ' With DLCG_WANTCHARS all regular keys work but no WM-CHAR message
             FUNCTION = %DLGC_WANTCHARS         ' doc says "WM_CHAR messages"
             'FUNCTION   = %DLGC_WANTMESSAGE
             EXIT FUNCTION

         CASE  %WM_CHAR                      '"An application should return zero if it processes this message. "
            ' LOWRD wparam = "the character code of the key"
             IF wparam = %VK_TAB THEN
                 ' standard TAB behavior
                   SetFocus       GetnextDlgTabItem(GetParent(hWnd), hWnd, (GetKeyState(%VK_SHIFT) < 0))
                   FUNCTION = 0
                   EXIT FUNCTION

             ELSE  ' not tab
                iChar  = LOWRD(WParam)
                SELECT CASE AS LONG iChar
                    CASE &h30 TO &h39, &h41 TO &h46, _    ' OK characters 0-9 and A-F
                         &h61 TO &h66, _                  ' lower case a-f, will be uppercased when they get in
                         %VK_TAB, %VK_HOME, %VK_END, %VK_BACK, _      ' expected control characters
                         %VK_RIGHT, %VK_LEFT, %VK_INSERT, %VK_DELETE, _
                         %vK_ESCAPE
[COLOR="Red"]    ' ******************************************
    ' AT THIS POINT YOU KNOW THE CHARACTER IS VALID, 
    ' SO HERE YOU CAN TEST IF YOU WANT TO ALLOW THAT 
    ' CHARACTER AT THIS POSITION BEFORE 'EXIT SELECT'  
    ' WHICH WILL ALLOW THE NORMAL PROCESSING OF THAT 
    ' CHARACTER
    ' *******************************************[/COLOR]
                        EXIT SELECT                      ' allow normal processing
                    CASE ELSE
                        MessageBeep  %MB_ICONHAND
                        FUNCTION = 0
                        EXIT FUNCTION    ' bypass normal processing
                END SELECT
             END IF

       END SELECT
       ' if message not handled (if handled proc was exited), call default handler
       FUNCTION = CallWindowProc (dwProc, hWnd, wMsg, wParam,lparam)

END FUNCTION

[Dave Biggs]

Subclassing is probably the way to go but just for fun here's another ..

#COMPILE EXE
#DIM ALL
%USEMACROS = 1
#INCLUDE "WIN32API.INC"
 
%BTN_Test      = 102
%LBL_LABEL1    = 101
%TXT_TEXTBOX1  = 100
'------------------
 
CALLBACK FUNCTION DlgProc()
 LOCAL sTest$, x&
  SELECT CASE AS LONG CB.MSG
 
    CASE %WM_COMMAND
      SELECT CASE AS LONG CB.CTL
        CASE %BTN_Test
          IF CB.CTLMSG = %BN_CLICKED OR CB.CTLMSG = 1 THEN
            CONTROL GET TEXT CB.HNDL, %TXT_TEXTBOX1 TO sTest
            MSGBOX "sTest = "+stest, ,"Result"
          END IF
 
        CASE %TXT_TEXTBOX1
          IF CB.CTLMSG = %EN_CHANGE THEN
            CONTROL GET TEXT CB.HNDL, %TXT_TEXTBOX1 TO sTest
            x = VERIFY (sTest , "-+,.1234567890")
            IF x > 0 THEN
              WinBeep 800, 50
              sTest = REMOVE$(sTest, MID$(sTest, x, 1))
              CONTROL SET TEXT CB.HNDL, %TXT_TEXTBOX1, sTest
              CONTROL SEND CB.HNDL, %TXT_TEXTBOX1, %EM_SETSEL, x-1, x-1
            END IF
          END IF
 
      END SELECT
 
    CASE %WM_SYSCOMMAND
      IF (CBWPARAM AND &HFFF0) = %SC_CLOSE THEN
        DIALOG END CB.HNDL
      END IF
 
  END SELECT
END FUNCTION
'------------------/DlgProc
 
FUNCTION PBMAIN()
 LOCAL hDlg  AS DWORD
 
  DIALOG NEW 0, "Test", , , 200, 120, %WS_CAPTION OR %WS_SYSMENU, TO hDlg
  CONTROL ADD LABEL,  hDlg, %LBL_LABEL1, "-+,.1234567890 allowed", 50, 25, 120, 20
  CONTROL ADD BUTTON,  hDlg, %BTN_Test, "Test", 75, 60, 50, 15
  CONTROL ADD TEXTBOX, hDlg, %TXT_TEXTBOX1, "", 45, 90, 100, 13
 
  DIALOG SHOW MODAL hDlg, CALL DlgProc
 
END FUNCTION
'------------------/PbMain

[Chris Holbrook]

seacrhing the forums using "superclass numeric" I came up with this:

http://www.powerbasic.com/support/pbforums/showthread.php?t=22947&highlight=superclass+numeric

[Michael Mattias]

Hmm... seems "IS NUMERIC" has at least as many definitions as does "Comma-separated Values file"

[Hubert Brandel]

>> If you are unfamiliar with SubClassing, there's a very good
>> starting example in the Samples folder on the PB disk.

Yes I am and I must be blind too ... now I found the SubClass Example

[Mark Strickland]

One suggestion

I wrote a edit control for FireFly. I did NOT take the approach of using a mask:

###,###.00

Type of formating. I found that a bit harder to program. I created category codes:

S10 = Any string up to 10 characters
N10.2 = Numeric with two decimals
Z8 = Digits Only and Left zero filled for a total of 8 characters
D1 = Date field

I have more but you get the idea. I found that parsing off the codes for the length and decimals then jumping to a section of code worked fairly easy.

Food for thought.

[Mike Doty]

I think Dave Biggs method could be expanded to type into a 1-character text box. The character could be checked against a format string and if
valid at the postion use CONTROL GET TEXT and then CONTROL SET TEXT adding the new character. I've seen floating textboxes used
with grids that are read only using a similar method.