Problem in listbox (to Antonio)

[driessen]

Antonio,

Since I use FWH 9.12, I noticed a problem in the listbox.

In the scrollbar, the block which can be used to scroll, has vanished. Also, the arrows on the scrollbar can't be used. The only way to scroll, is using the arrow keys on my keyboard.

If I use FWH 9.11 again, the block in the scrollbar is back and everything is running fine.

What is the cause of this behaviour ?

Thanks a lot in advance.

[Antonio Linares]

Michel,

Please comment this line in FWH\source\classes\scrllbar.prg:

Code: Select all  Expand view

METHOD SetPage( nSize, lReDraw ) CLASS TScrollBar

   local nFlags

   DEFAULT lRedraw := .f.

   // nSize = Max( 10, nSize )
   
   if ! Empty( ::hWnd )
      ...
 

[driessen]

Antonio,

I'm sorry but your suggestion is not helping.

I still use FWH 9.12 but I added SCRLLBAR.PRG from FWH 9.11.
Everything is working fine now.

Thanks for your help.

[Antonio Linares]

Michel,

These are the only changes from FWH 9.11 to 9.12 in Class TScrollBar:

Commenting the line that I told you it should solve it.

[driessen]

Antonio,

I'm leaving on holidays for the week to come.

I'll try it out when I'm back. If necessary I put a message here.

Thanks a lot for your efforts.

[driessen]

Antonio,

I took a closer look at the problem in the scrollbar of the listbox.

Even in FWH 10.1 I noticed that the problem is in SCRLLBAR.PRG. The cause has to be found in this code :

Code: Select all  Expand view

METHOD SetPage( nSize, lReDraw ) CLASS TScrollBar

   local nFlags

   DEFAULT lRedraw := .f.

   // nSize = Max( 10, nSize )

   if ! Empty( ::hWnd )
      nFlags = SB_CTL
   else
      if ::lVertical
         nFlags = SB_VERT
      else
         nFlags = SB_HORZ
      endif
   endif

   ::nPgStep = nSize

   SetScrollInfo( If( ! Empty( ::hWnd ), ::hWnd, ::oWnd:hWnd ),;
                  nFlags, nSize, lReDraw )

return nil
 

No block is visible in the scrollbar.

If I change it this way (/* and */) :

Code: Select all  Expand view

METHOD SetPage( nSize, lReDraw ) CLASS TScrollBar

/*
   local nFlags

   DEFAULT lRedraw := .f.

   // nSize = Max( 10, nSize )

   if ! Empty( ::hWnd )
      nFlags = SB_CTL
   else
      if ::lVertical
         nFlags = SB_VERT
      else
         nFlags = SB_HORZ
      endif
   endif

   ::nPgStep = nSize

   SetScrollInfo( If( ! Empty( ::hWnd ), ::hWnd, ::oWnd:hWnd ),;
                  nFlags, nSize, lReDraw )
*/

return nil
 

everything is working fine. The block is visible and useable in the scrollbar.

Any idea ?

Thanks a lot in advance.

[driessen]

Antonio,

Were you already able to look at the problem in the scrollbar ?

Thank you in advance.

[driessen]

Antonio,

Were you already able to read my question ?

Thanks.

[Enrico Maria Giordano]

Can you show a reduced and self contained sample of the problem?

EMG

[Antonio Linares]

Michel,

Yes, it seems as we are wrongly calling SetScrollInfo().

As a temporary workaround you can do as you have done: simply comment out the entire method source code.

[driessen]

To Antonio.

Antonio, I looked to some previous versions of FWH.

In FWH 9.01 till 9.11, the setpage methode is commented out completely.

In FWH 9.12, the methode is activated. At this moment, the problem has started.

I comment it out again (also in FWH 10.1) and everything is working fine again.

Thanks.


To Enrico.

In any example where a listbox is used, the problem occurs.

[Enrico Maria Giordano]

Ok. Try adding the following source to scrllbar.prg:

Code: Select all  Expand view

#pragma BEGINDUMP

#include <windows.h>
#include <hbapi.h>

HB_FUNC( SETSCROLLRANGE )
{
   SCROLLINFO si;

   si.cbSize = sizeof( si );
   si.fMask  = SIF_PAGE | SIF_RANGE | SIF_DISABLENOSCROLL;
   si.nPage = 1;
   si.nMin  = hb_parni( 3 );
   si.nMax  = hb_parni( 4 );

   hb_retnl( SetScrollInfo( ( HWND ) hb_parnl( 1 ), hb_parni( 2 ), &si, hb_parl( 5 ) ) );
}

#pragma ENDDUMP

EMG

[driessen]

Enrico,

Thanks a lot.

Your solution saved the problem.

Antonio,

Could you correct SCRLLBAR.PRG in FWH 10.2 ?

Thanks a lot.

[Antonio Linares]

Michel,

Fix included for next FWH 10.2

Enrico, many thanks!

[driessen]

Antonio,

Thanks a lot.