Re: AHPP in scs2pdf

On Wed, Mar 13, 2002 at 02:24:57AM -0700, James Rich wrote:
> On Wed, 13 Mar 2002, Frank Richter wrote:
>
> > Function scs2pdf_ahpp in scs2pdf.c doesn't handle positioning right,
> > if *curpos is lower then position. Wenn you make a report with
> > HIGHLIGHT attribute, AHPP is used to position the cursor back to the
> > start of this field and overprint a second time, to get a bold output.
>
> Hmm... I thought that if the current position is greater than the position
> given by AHPP (that is what the patch says, contradicting what you say
> above) that the printer should go to the next line and move over to the
> position indicated.  I'll reread that documentation.

I just looked at the scs file and compared to the output generated by
our printers. AHPP with positioning back and reprinting the same string
gives bold text in all cases (HPT to Kyocera Lasers and simple IBM
Proprinter attached to real 5250 Terminals).

> I'll think about how to get bold output.  It really shouldn't be too hard.

I think, we need to collect the line in memory and tag characters (in a
second array), that have to be printed in bold. The output routine can
then switch fonts bold as needed. Perhaps we can even use this logic for
switching fonts and cpi, when indicated by scs commands.

> If the behaviour you describe is what is supposed to happen then maybe we
> can know which characters are supposed to be in bold.  The only trouble is
> if we get the bold attribute (meaning AHPP go back and retype) after the
> characters that are supposed to be bold and we have already flushed the
> buffer we might be in a tricky spot.

We should flush at the next newline ore page break. We must provide a
larger buffer, if it get's filled by a long line with bolded text. And
the output function should flush in smaller peaces, if we have more then
255 characters collected in the buffer.

> If AHPP is less than the current position and we are supposed to retype
> the characters for a bold effect, that does mean that the characters
> received after AHPP are the same as the characters received just before
> it?

Yes.

> > I found no easy way, to switch to and back from a bold font, but
> > the following patch should at least print the second string in the right
> > place:
>
> Okay, I'll review the docs and see if they agree.  With this patch do your
> printouts look right?

Yes, they do.

--
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Frank Richter, Leiter EDV
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