Re: [hpoj-devel] Re: xojpanel 20 character patch

[<pa...@rc...>]

Joe Piolunek wrote:
> I attached a patch that should fix it, though it's hard to guess which fonts 
> a user will have installed. The "Courier" font is specified now. Hopefully, 
> most users will have it or something similar. Courier displays as fixed-width 
> on my system.
Thanks.  That looks much better IMO.  It's checked in now.  Was it set to
Courier in 0.7?  It now looks like the way it used to font-wise anyway.

> On another subject, there now seems to be an intermittent scroll timing 
> problem in xojpanel's "lcd". It appears to be related to the printer polling 
> code in (or called by) XojPanel::getPrinterLCDMessages() . When I commented 
> out the polling code and substituted fake Line1 and Line2 strings, the 
> problem went away. I don't think my changes caused it, but I'll keep looking. 
> Is there something in the ptal code that could result in a delay in returning 
> the lcd strings?
I was afraid that might happen.  :-(  It's a combination of the slower
parallel-port I/O in ptal-mlcd and the higher latency in libptal due to its
waiting for the GetReply before returning, as opposed to the applications's
polling for the reply the way it was done with ojlib.  I'm going to try to
address the first problem eventually, and I probably should re-institute an
alternative non-blocking PML API in libptal for the sake of xojpanel, at the
expense of a little more code complexity.  It might also help for me to
implement PML traps (also on my TODO list), which is where the peripheral
notifies the host of changes in value of a PML object so the host doesn't
have to poll periodically.  The disadvantages of traps are that they aren't
100% reliable and they aren't practical over a network (i.e. through a
JetDirect).

David