[sane-devel] Behavior when sane_read() returns SANE_STATUS_EOF?
Tue, 25 Feb 2003 15:45:54 -0500
>> with SANE_STATUS_EOF? Will/should the frontend abort the scan, or
>> gracefully truncate the output? (Or fill the remaining output with
>Print a warning and ask the user what to do. Or let the user decide by
(What do the current frontends do?)
>> I guess another version of my question is: If the backend cannot be
>> *certain* that it will deliver 'lines' lines of data, is it required
>> to set 'lines' to -1? (Or, can/should it provide the optimistic
>> intended image size, which assumes that the paper is long enough?)
>You're speaking about a sheet-fed scanner? I'd use lines = -1 in this
>case by default. Maybe add an option "image size" (A4, Legal,
>automatic) and use lines = -1 for automatic and a fixed size for the
Yes --- I'm on the verge of better supporting a sheet-fed Microtek (older)
scanner. A user can legitimately specify a fully-defined scan area
(upper-left corner, lower-right corner), which is fine if the scan area
actually fits on the page they stick into the slot. If not, the backend
has to react somehow.
I guess it just seems a little odd for the backend to always say
'lines = -1', even if it knows exactly what the line count should/could
be (if enough sheet is in there).
I'll play around with it, in any case...