include "fivewin.ch"

function main()

 local oWnd, oLbx

 SET DELETED ON
 SET EXCLUSIVE OFF
 use customer

 define window oWnd title "Test Browse"

 @ 0 , 0 listbox oLbx fields alias "customer" of oWnd

 oWnd:oClient:= oLbx

 activate window oWnd MAXIMIZED

return nil

Enrico,
I've tested your last sample.
Slowness is less evident.

I propose to slightly modify your program to make it more like a real work situation.
I don't believe that in your network you have good performance again.

I'm not talking about a failure.

I want to know if is it possible to rearrange this excellent class to obtain better performance with a drastically reduce of traffic on network.

Problems perhaps are elsewhere.

I'm comparing software for viewing picture written by myself and other famous applications
even in this case there is a little difference in refresh rate

good evening

#include "Fivewin.ch"


FUNCTION MAIN()


    LOCAL oDlg, oBrw, i

    ANNOUNCE RDDSYS

    SET DELETED ON
    SET EXCLUSIVE OFF
    USE CUSTOMER EXCLUSIVE

   COPY TO custtemp

    FOR i := 1 TO 1000
        APPEND FROM custtemp
    NEXT i

    INDEX ON field->first TAG first TO customer
    INDEX ON field->last  TAG last  TO customer
    INDEX ON field->city  TAG city  TO customer
    INDEX ON field->state TAG state TO customer
    INDEX ON field->zip   TAG zip   TO customer

    USE
    USE customer SHARED
    SET INDEX TO customer

    DEFINE DIALOG oDlg

    @ 0 , 0 LISTBOX oBrw FIELDS

    ACTIVATE DIALOG oDlg;
             ON INIT ( oDlg:Maximize(),;
                       oDlg:SetControl( oBrw ) );
             CENTER

    RETURN NIL

INIT PROCEDURE RddInit
REQUEST DBFFPT
REQUEST DBFCDX
rddSetDefault( "DBFCDX" )

Ok, the difference seems to be the SHARED clause, that is expected. With SHARED clause I can see the slow refresh even without indexes. I don't know if TWBrowse can be improved but the major benefit would be in improving DBF's shared access speed, if it were possible.

EMG

Ok Enrico
Thanks

I don't know if TWBrowse can be improved but the major benefit would be in improving DBF's shared access speed, if it were possible.

Method LostFocus()
   ::lHasFocus:=.f.
    // copy visible records to buffer array
return nil

Methd GotFocus()
  ::lHasFocus:=.t.
return nil

Method Paint()
   ...
   if ::lHasFocus
     // paint using records
   else
      // paint using buffer array
   endif
   ...
return nil

Enrico,
James's suggestion is very very interesting.
Thanks

Here is a possible solution. In the LostFocus() method, copy all visible records into a buffer array. Then during refresh if the control does not have focus() then repaint using the array, otherwise repaint by reading records from the source.

When the control gets focus, reset the lHasFocus variable to .t.

Excuse me,
in these days I'm under pressure.
I've forgot to tell you that I tested your samples
It's a valid solution except for a little visual effect
There is a little flickering in your sample and in this (rewritten by me) there are
other problems that I am not able to resolve.

This is the only one working solution at the moment.
In my opinion to load into an array only visible cells would be a first step to improve browsing classes

include "fivewin.ch"

xtranslate DelObj <o> => If <o> != nil; DeleteObject( <o> ); endif; <o> := nil

REQUEST HB_GT_GUI_DEFAULT

ANNOUNCE RDDSYS

FUNCTION MAIN()
LOCAL oDlg

LOCAL oBrw
LOCAL aRec := {}

LOCAL nIni
LOCAL nRig
LOCAL nFin
LOCAL nCur := 1

SET DELETED ON
SET EXCLUSIVE OFF
USE customer
SET INDEX TO customer

nRig := 20
nIni := 1
nFin := 1

DEFINE DIALOG oDlg RESOURCE "DIALOGO"

oBrw := TXBR3():Redefine( 101, , oDlg )

ACTIVATE DIALOG oDlg

RETURN NIL

CLASS TXBR3 FROM TWBROWSE

CLASSDATA lRegistered AS LOGICAL // used internally

DATA hSaveScr

METHOD Paint()
METHOD Destroy()

ENDCLASS

METHOD Paint() CLASS TXBR3

local aInfo

if ::hSaveScr != nil .and. GetFocus() != ::hWnd
aInfo := ::DispBegin()
DrawBitmap( ::hDC, ::hSaveScr, 0, 0 )
::DispEnd( aInfo )
else
Super:Paint()
DelObj ::hSaveScr
::hSaveScr := WndBitMap( ::hWnd )
endif

return nil

METHOD Destroy() CLASS TXBR3

DelObj ::hSaveScr

return Super:Destroy()

INIT PROCEDURE RddInit
REQUEST DBFFPT
REQUEST DBFCDX
rddSetDefault( "DBFCDX" )

There is a little flickering in your sample and in this (rewritten by me) there are other problems that I am not able to resolve.

up

Since in a dialog I have other obiects... is it possible in Paint method to check Focus of entire dialog instead of TWBROWSE object?