Re: Scroll bars

[boothm@xxxxxxxxxxxxxxxxx]

There's a couple of things on scroll bars that are relevant.  I was all 
excited about them but am less so now.  First, to set a scroll bar you use 
the regular keyword you use for SFLEND(*MORE) but insert *SCRBAR  like 
this:  SFLEND(*SCRBAR *MORE).  That allows non-enhanced terminals to use 
the regular *MORE display.

But beyond that:  if your users reverse their roll keys then the scroll 
bar is all futzed up and doesn't know what to do, so it fails 
ignominiously.  (I may be wrong  - I sure hope someone corrects me on this 
point.)

Also, the scroll bar only scrolls the subfile itself, so it can't scroll 
you to records you haven't loaded.  With big record counts a scroll bar is 
not useful.  But, if you are loading the whole subfile they work fine. 
You'll want to pass the record count into the DDS format SFLSIZE(&NBRREC) 
where NBRREC is a field on the DDS screen defined as a P field.  That 
allows the scroll bar's shaft length to reflect the relative size of the 
displayed panel vs. the whole subfile.

A final point you may not pick up on as you fool around with the scroll 
bar:  We're used to pages scrolling a page at a time;  the scroll bar 
allows you to scroll partial pages, too, and, if you click the top/bottom 
of the scroll bar, the records advance and recede one record at a time 
which is useful to point out to users.

About the size of the subfile:  aside from all of the emotion of the 
issue, I found that at some point between 2,500 records and 5,000 records 
the "fineness" of the scroll bar adjustment became too difficult for most 
users to control the panels and stop where they wanted to stop.  On a RISC 
box I loaded a 5,000 record subfile in about 11 seconds.  2,000 record 
subfiles are loading in 2 to 3 seconds.

there is a scroll bar sample at http://www.midrange.com/booth

Have fun.  (I'd love to hear how it turns out, and see a screen shot if 
you were so inclined.)

_______________________
Booth Martin
boothm@earth.goddard.edu
http://www.spy.net/~booth
_______________________




jun.galido@zurich.com
Sent by: owner-rpg400-l@midrange.com
11/24/1999 02:28 AM
Please respond to RPG400-L

 
        To:     RPG400-L@midrange.com
        cc: 
        Subject:        Scroll bars



Does anyone know how I can incorporate scroll bars on my screen?  Can I 
ask for
a sample code?

Thanks.


+---
| This is the RPG/400 Mailing List!
| To submit a new message, send your mail to RPG400-L@midrange.com.
| To subscribe to this list send email to RPG400-L-SUB@midrange.com.
| To unsubscribe from this list send email to RPG400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner/operator: david@midrange.com
+---