RE: [hpoj-devel] patch to improve scan speed/robustness

[Joe P. <joe...@sn...>]

On Mon, 30 Oct 2000, PASCHAL,DAVID (HP-Roseville,ex1) wrote:

<....>
> 
> > The LCD  line 1 text scrolls now when it's too long. I 
> > haven't been able to
> > test scrolling on line 2, but it looks like it might work.

> One concern I have here is that sometimes the peripheral does its own
> scrolling when the message is too big for the actual LCD.  If your display
> is smaller and you're trying to do your own scrolling as well, then it might
> not be too pretty.  I'm not sure what the best way would be to figure out
> how large to make the display, but perhaps you could make it grow
> dynamically whenever you got back a string with more printable (non-null,
> non-space) characters than you already had room for.  Since I'm not familiar
> with QT I don't know how hard this would be.
> 

If all of the officejets always send the complete string to xojpanel, xojpanel
shouldn't be affected by the printer's scrolling action. I'm not sure what you
mean, though. Are you saying that some printers can send sections of a string
rather than the whole thing? 

What I see happening with the 600 is xojpanel gets a full text string from the
printer, even if it's too long for either display. The code I added to
xojpanel simply scrolls it horizontally (independant of the printer) on the
xojpanel lcd window until the string coming from the printer changes. The
printer is queried every 1000ms presently.  The 600's hardware lcd scrolls the
same long line independantly of xojpanel. The xojpanel LCD has two rows of 16
"blocks" to show one character in each. The 600's LCD has only one row of 16
blocks. While the printer's LCD is scrolling the long string in its one line of
blocks, xojpanel scrolls the string independantly in the upper line of its own
"lcd". 

The only officejet I have access to is my 600, which has only the one text line
on its hardware lcd. It probably never sends a line2. That prevents me from
properly testing line 2 scrolling.  Code for second line display and scrolling
is in xojpanel now, though.

Are there any officejets that have a second line on their LCD? Do any of them
have a second line that would ever need to be scrolled? The answers
probably aren't necessary right now, but they could be helpful.

If you haven't downloaded my changes yet, and are not in a hurry, wait just a
bit. I just found and hopefully corrected another bug (a memory leak) and will
probably put the new code on my site tomorrow.

**********************************************

Joe