Slow input on a READ with a scanner

[Tim J]

If I use a handheld scanner to scan a barcode, it is very slow in a Harbour compiled application.  The longer the barcode, the more time it takes to input the text.

It's as if a fairly fast typist is typing in the barcode.

If I scan the same barcode within a Command Prompt, it is instantaneous for all intents and purposes.

Is there anyway to speed this up?

If you have a scanner, you can try the following code:

FUNCTION MAIN
LOCAL ;
getlist := {}, ;
cString := space(25)
CLS
Do While .T.
cString := space(25)
@ 12, 30 say "Scan barcode:" GET cString
READ
@ 20, 0 say cString
Enddo
Return .T.

Thanks,

Tim

[david...@gmail.com]

Hi Tim,

It's been a while since I programmed in console mode but why would you need the "Do While" for?

As I remember, READ will stop execution of following lines until it has been issued an Enter or esc key .

Could it be that the DO While is making it seem slow?

Regards,

David Field

[Hurricane]

Hi Tim,

Initially just try this:

cString := space(25)
@ 12, 30 say "Scan barcode:" GET cString
READ

Some devices can send control characters, their looping code can make it difficult to understand and read.

In Clipper, x/Harbour I have already integrated with some devices (Code Reader, Data Collectors, Tax Printers, etc.) If approved, next week I will start integration with facial access controller.

Regards,

[Damian Sz.]

Hi Tim

Configure the barcode scanner to send a prefix before the barcode, e.g., the  ` (96) character, and a suffix  ENTER. Use the SetKey() function to call the code retrieval function when it detects the ~ character. Pass the function result to the GET variable.

#define K_BARCODE_PREFIX    96 

SetKey() with the implementation of "send the ENTER key" and "check if you are in the GET field that is ready receive the barcode":

SetKey( K_BARCODE_PREFIX, {|p,l,v| cB:=BarCodeRead(), iif( v == 'BARCODE', __KEYBOARD( Chr( K_CTRL_Y ) + cB + Chr( K_ENTER ) ), "" )} )

slightly different implementati:

SetKey( K_BARCODE_PREFIX, {|p,l,v|iif( v == "BARCODE", Eval( {|| cB := BarCodeRead(), GetList[1]:varPut( cB )} ), "") } )

FUNCTION BarcodeRead()
  LOCAL cBarcode  := ""
  LOCAL nKey          := 0
  LOCAL nTime       := Seconds()
  LOCAL nTimeOut := 5

   DO WHILE ( Seconds() - nTime ) < nTimeOut
         nKey := INKEY( 0.2 )
         IF nKey != K_ENTER
             IF nKey != 0
                 cBarcode += CHR( nKey )
             ENDIF
         ELSE
            EXIT
        ENDIF
   ENDDO

RETURN AllTrim( cBarcode )

nTimeOut is there to prevent an infinite loop in case you accidentally press ' and do not send the barcode.

Regards

Damian

[Tim J]

David, The Do While loop was simply to enable me to scan multiple times with different barcodes and watch the results in my test.  

Thanks

[Tim J]

Damien Sz, I can see where your proposal would work.  Thanks

[Tim J]

Hurricane, that is what I do.  I should have left the Do While loop off the sample I posted.  Thanks

[António]

I had the same issue.
Try adding

-gtwvt

to the hbm file.
Scan will be fast.
António

[Tim J]

That did it!!!!

Thank you so much Antonio!

[Paola Bruccoleri]

Hi Tim

Before get, put

CLEAR TYPEAHEAD
@fila1,col1 get cCodBar

---

De: "'Tim J' via Harbour Users" <harbou...@googlegroups.com>
Para: "Harbour Users" <harbou...@googlegroups.com>
Enviados: Martes, 13 de Febrero 2024 12:27:22
Asunto: [harbour-users] Slow input on a READ with a scanner

--
You received this message because you are subscribed to the Google Groups "Harbour Users" group.
Unsubscribe: harbour-user...@googlegroups.com
Web: https://groups.google.com/group/harbour-users
---
You received this message because you are subscribed to the Google Groups "Harbour Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to harbour-user...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/harbour-users/c0688870-f188-49e6-955f-dabdd6b68403n%40googlegroups.com.

[Tim J]

Thanks Paola, but that didn't work for me.

Antonio's solution did make the scan basically instantaneous - which is terrific!

It added a few other consequences that I can live with, or work around, though:

1) It changed the font and font size, making the screen size different.

2) If the application is called from a batch file, if leaves the calling screen open.  Got around that by using the "START " command

3) It slowed down long intensive calculations by a factor of 33% or so.

[AL67]

Harbour in console mode (text gt) very slow display screen

Try this code:

FUNCTION MAIN

LOCAL ;
getlist := {}, ;
cString := space(25)
CLS

@ 20, 0 SAY "Read:"

Do While .T.
cString := space(25)

DISPBEGIN()

        @ 0, -100 GET cString   //out of screen
READ

        DISPEND()
@ 20, 7 say cString
Enddo
Return .T.

[Tim J]

Thanks AL67, but that didn't seem to help.

Antonio's solution is still my answer.

[viktor....@googlemail.com]

I had a similar problem on a different topic. I wanted to enter entire CSV lists via copy & paste using GET fields in a CMD application. In case of an error, everything in the buffer should be cleared with

CLEAR TYPEAHEAD
KEYBOARD CHR( 0 )

Unfortunately, this did not work correctly when there were too many characters in the copy buffer. Only part of it was deleted. sometimes more, sometimes less.

With a bit of experimenting, I discovered some strange behavior. If, after calling INKEY(), LASTKEY() must be called at least twice then the readout speed from the key buffer increases enormously.

Example:

do while !EMPTY( ineky( 0.1) )
  lastkey()
  lastkey() 
enddo

As a result, adjustments in getlist.prg significantly accelerated GET input.

METHOD Reader( oMenu, aMsg ) CLASS HBGetList

......

      DO WHILE oGet:exitState == GE_NOEXIT .AND. ! ::lKillRead

         IF oGet:typeOut

            oGet:exitState := GE_ENTER

         ENDIF

         DO WHILE oGet:exitState == GE_NOEXIT .AND. ! ::lKillRead

            IF !EMPTY( Inkey( 0 ) ) .AND. !EMPTY( lastkey() )

#ifdef HB_COMPAT_C53

               SetCursor( iif( ::nSaveCursor == SC_NONE, SC_NORMAL, ::nSaveCursor ) )

               SetCursor( SC_NONE )

#endif

               ::GetApplyKey( lastkey(), oGet, oMenu, aMsg )

               nRow := Row()

               nCol := Col()

               ::ShowGetMsg( oGet, aMsg )

               SetPos( nRow, nCol )

            ENDIF

         ENDDO

#ifdef HB_COMPAT_C53

         IF ! ::nLastExitState == GE_SHORTCUT .AND. ;

            ! ::nLastExitState == GE_MOUSEHIT .AND. ;

            ! ::GetPostValidate( oGet, aMsg )

#else

         IF ! ::GetPostValidate( oGet, aMsg )

#endif

            oGet:exitState := GE_NOEXIT

         ENDIF

      ENDDO .......