Hi, On Tue, Dec 10, 2002 at 07:47:08PM +0100, Oliver Rauch wrote: > On Tuesday 10 December 2002 01:35, Henning Meier-Geinitz wrote: > > I don't even know how to implement the "simple" callback over the > > network. For a double callback, oh well. I don't want to think about > > I do not understand where you see the problem with a callback over the > network. > > > frontend----sane-net=======saned----backend > > backend calls callback of saned. saned sends info about callback to sane-net > and transmits the text that shall be displayed. sane-net calls callback of > frontend. When we do not use any selections then the backend does not > need a feedback when/if the text is displayed.
After Matto's and mine discussion about the auth_callback I think you are right. But adding the message callback means that we need to add at least one parameter to every reply of a SANE_NET RPC that should be able to display messages. Two, if we add a window (or other reference) parameter. Speaking of which functions should be able to call the callback: At least sane_start, because of the calibration/warm up message Other options that may make sense? Which function to use to supply the callback pointer? I propose sane_open, because then the backend knows, which device calls the callback. Bye, Henning