{i} This page state about a scanner service in freedesktop. This document was started off a discussion at xdg mailing list : http://lists.freedesktop.org/archives/xdg/2007-January/009074.html

Goals

• Monitor buttons

• Share devices These feature imply that the software own the device handle, this is why the software expose acquisition API.

• Acquire image

Achievement

This can be done through a dbus system wide daemon.

DBus API

This is a rough draft of an API -- ?EtienneBersac 2007-01-28 22:21:45

• device_list ?GetDeviceList
• string ?GetDeviceInfo (device)
• option_list ?GetDeviceOptions (device)
• ?ShareDevice (device, boolean)
• job ?StartScan (device, settings)
• ?StopScan (job)

• ?GetImage (job) /!\ How to monitor ? How to get buttons events ? How should the image be transferred back to the client?

• A file descriptor or device node might be one way for transferring the image quickly (sending it directly over D-BUS definitely wouldn't work). Signals :

• device-plugged (device)

• device-unplugged
• button-pressed (device, button)
• job-done (job)

Scanner access

Scanner access is done through the famous SANE library. Hope that HAL & SANE will work better together in the future in order to get devices from HAL.

Sharing

SANE has a net scanning protocol. However, it shows some limitation (basically, it's too slow for huge image). What to do ?

• It would be nice to come up with a new protocol for this like the D-BUS one, maybe with some kind of compression, like bzip2. I wouldn't worry about breaking compatibility. -- ?DonaldStraney