[sane-devel] scanner buttons

[m. allan noah]

On Fri, 9 Jul 2004, Gerhard Jaeger wrote:

> On Friday 09 July 2004 16:09, m. allan noah wrote:
> -------------------------------8<--------------------------
> > ok, here's a crazy idea- why not just reload the entire option array every
> > few seconds? 
> 
> then we get some kind of "Flash" application, which does nothing than simply
> reloading/repainting its surface :-))))))
> Who will control the reload - a timer inside the backend?

i would think that perhaps a named option like 'reload_interval' could set 
the number of seconds between reloads. then the front-end could set the 
timer or whatever (or ignore it).

> 
> > the backend then gets to decide what order to reload them in 
> > (i.e. load the 'mode' switch first, then change all the mode params, then
> > load the 'scan' button press).
> >
> > is this nuts?
> 
> Hmmm, I'm not really sure at the moment :-))))))))))))))))
> 
> But in the end we need some more feedback, which can be shown to the
> user of a backend.
> 

yes, and since the scanner often returns button presses or lamp status or 
whatever as a bit-mask, it would seem that handing the control over to the 
backend every few seconds, and let it change all the option descriptors it 
needs to, would be a heck of alot simpler than setting a cap on each 
possibly changeable option, and having the front-end spend all it's time 
looping over them.

in the case of a scanner button changing the mode, which might hide some 
options (i.e. no bit-depth drop-down in lineart mode) the screen was going 
to have to be re-drawn anyway.

allan

> Ciao,
>   Gerhard
> 
> 
> 

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