Scanner infrastructure in freedesktop

[Étienne Bersac]

Hi,

> I don't see any problem with using only SANE, since it's the standard
> Linux scanner API.  If it's missing something major then it's probably
> easier to just add support for it to SANE than to come up with a whole
> new backend system, which just complicates things (and adds too many
> abstraction layers).

I agree, SANE is the main (by far, i'm even implicated in SANE) scanner
support for Linux and most UNIX systems. However, one of the main goals
of TWAIN 2 is Linux/Unix port. So there might one time a need for other
backend.

> Starting a scan through a dbus API could be
> useful, but since there's just one backend (SANE) instead of
> completely different ones for KDE or GNOME, it would be easier to just
> link scanning programs with libsane.

That's easier, of course, but where is button handling ? hotplug ?
(easy) sharing ? We need some kind of daemon. Luckily, Martin Owen is
working on HAL scanner support. But we still need some "middle" software
between drivers and end user gui. Gui must not load drivers them
selves !!!

>   Also, it seems like it would be
> sort of inefficient, since the entire image would either have to be
> stored in a temporary file and deleted by the program (involves a lot
> of disk I/O) or the entire thing would have to be passed over dbus,
> which wasn't meant for that kind of thing.

Agree. This is why i added "maybe" :). This is subject to discussion.
I'm not a dbus guru at all.

> Modifying SANE to work with dbus would be the good part, though, since
> then when it searches for supported scanners, it could use Avahi or
> HAL to detect scanners and possibly use the info from HAL to configure
> them.

Remember that SANE intend to work on WIN32, OS X, Linux and other UNIX.
The bad thing in this is that, instead of modularize detection and
sharing, they reinvented their own systme which leads to the current
situation …

> For example, KDE
> and GNOME could have scanner action config dialogs where you can set a
> program to launch when the "scan" button on the scanner is pressed.

Yes, like Vista does already. Even Gnome Volume Manager has an
(unimplementable) entry for scanner.

> Actually, it would be nice to have some way for programs to register
> themselves for this, since it would be a pain for the readme for a new
> scanner program to have to tell people to go to config dialog X and
> add a certain command in a certain place.  Maybe there could be a
> directory where .desktop files would be stored?

Very nice idea. A kind of "prefered-application" like manager.

> Anyways, sorry for the rambling, but some kind of scanner
> infrastructure that takes advantage of all this stuff would be great.

I do fully agree with you :)

Étienne.
-- 
Verso l'Alto !
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