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)
![/!\](/moin_static193/freedesktop/img/alert.png "/!\"){kind=small}
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