On Sun, Jun 28, 2020 at 7:09 PM Alexander Pevzner <p...@apevzner.com> wrote: > > So my question is: What can I do in order to monitor ADF status? Call > > sane_start() after setting an empty > > scan region, so the scan is done at the first call to sane_read()? This is > > obviously not an option, as in the > > case of a loaded feeder this would consume the first original rather than > > just read ADF status. > > Cancel the scan immediately after sane_start() using sane_cancel()? I have > > no idea whether this is possible. > > There are actually no such API that will return ADF status before actual > scan attempt. >
This is not exactly true. Several sane backends present read-only options which report the status of various hardware sensors. Unfortunately, these options are generally inconsistent between backends. A few of them do have an option called "page-loaded", which should be used for this purpose. Look for SANE_NAME_PAGE_LOADED in the source, you will find them. allan -- "well, I stand up next to a mountain- and I chop it down with the edge of my hand"
