[sane-devel] Preview mode puzzle (re-send in text mode -- sorry)

[Mark Pemburn]

Hi,

    In my Mac/OS X project, I've reached the point where I can set the 
mode, resolution and depth and I now want to tackle the preview mode.  
In my early tests, it seems that setting the preview option to SANE_TRUE 
does _not_ do what I expect -- that is, it doesn't override the current 
settings of the other options.  The API doc says:

"A backend is free to override the resolution value with its own choice 
for preview mode, but it is advised to leave this choice to the frontend 
wherever possible.
This option is not mandatory, but if a backend does support it, it must 
implement it in a manner consistent with the above definition."

   The puzzle is, how do I know if the backend has chosen to override 
the currently set resolution value?  Unless I can divine this, it looks 
like I'll have to save the current settings, reset to what I decide is a 
suitable resolution, etc., then reset to the saved settings.  Is this 
correct?

Regards,

Mark