Guy Brooker wrote: > The Image Capture API also wants the the TWAIN DS to implement DEVICEONLINE > status, presumably for some UI indicator. > > Checking if the scanner is in the device list isn't really going to work, as > that will only determine if the device is plugged in. Infact, the way the > API works on OS X, the data source will only ever be called if the device is > plugged in, and it will be pulled down if the device is unplugged, so it > will always be in the device list. > > I could just return TRUE for that call, but I assume there may be some > scanners which won't scan until the lid is closed, or something like that. > Would sane_start() be enough to make sure the scanner is ready, or will it > only fail on the first call to sane_read() ?
I'm afraid that calling sane_start can be a bit "expensive": the sane_start call may take a few seconds, if the scanner performs for example a CCD line calibration. Abel
