[sane-devel] Re-reading options with Xsane

Henning Meier-Geinitz henning@meier-geinitz.de
Thu, 23 May 2002 19:55:22 +0200


On Wed, May 22, 2002 at 05:27:49PM -0700, Dave Close wrote:
> It is possible to define a backend option as SANE_CAP_SOFT_DETECT only.
> Such options are essentially read-only information sources for a frontend.
> Xsane reads the value of such an option and displays it in a grayed-out
> form. That seems natural and correct to me.
> But the value of such an option may change over time. Is there any way to
> cause Xsane to re-read the option and display the new value? Preferably, 
> without having to initiate a scan or other physical action?

In sane_control_option, you can set *info = SANE_INFO_RELOAD_OPTIONS
whenever any option is set or read. If your value can change even if
no other option is changed, the user must force a reload by pressing
is button (option type SANE_TYPE_BUTTON). The backend can set
SANE_INFO_RELOAD_OPTIONS when this option is set.