Hi, That's very nice to have button handling in your backend. Please provide semantic button naming like "paper-in", "trigger", "cancel" or default to "auto" or something similar. Also, please use boolean rather than 0/1 int option for button, this is as well more semantic. Button naming can be done per model, without modifying the underlying option handling (based on button number).
I'm telling you this, writing hal-scanner support which should help a lot on makeing use of scanner buttons in frontend like GNOME Scan and KDE. The idea is to help as much as possible the frontend to auto determine what to do on button event. I would like to open a discussion about button naming for 1.2, once i have a reasonnable hald-addon-scanner version. Regards, ?tienne.